Materials Science and Technology

INSTITUTO DE CIENCIA DE MATERIALES DE ARAGÓN
ARAGÓN MATERIALS SCIENCE INSTITUTE
INSTITUTO DE CIENCIA DE MATERIALES DE ARAGÓN
Consejo Superior de Investigaciones Científicas – Universidad de Zaragoza
Sede Campus Plaza San Francisco: Facultad de Ciencias: Pedro Cerbuna 12, 50009 Zaragoza
Sede Campus Río Ebro: Edificio Torres Quevedo, María de Luna 3, 50018 Zaragoza
Teléfono: 976 76 12 31
Fax: 976 76 24 53
http://www.unizar.es/icma/
1
Fondo de la portada / Background:
Microfotografía de la mesofase columnar observada en un cristal líquido "tipo banana".
Polarized optical microphotograph for the columnar mesophase observed for a banana-shaped liquid
crystal.
Imagen de la izquierda / Left figure:
Cerámica de lustre de Manises, siglo XV. Cortesía del Museo de Cerámica, Barcelona.
Lustre ceramic from Manises, circa XVth century. Courtesy of Museu de Ceràmica, Barcelona, Spain
Imagen de la derecha / Right figure:
Disposición casi lineal de átomos metálicos (en amarillo) en el primer compuesto con una cadena
hexametálica de iridio. Este oligómero 1-D, con aspecto de cobre metálico, es un fragmento molecular de
un "hilo metálico" relacionado con cadenas metálicas infinitas de valencia mixta, como las sales de
Krogmann. (Tomado de la portada de Angew. Chem. Int. Ed.)
The almost linear array of metal atoms (in yellow) in the first hexanuclear iridium-chain. This 1-D
oligomer is a molecular piece of a “metal-wire” related to the infinite mixed-valence metal chains, such
as the Krogmann salts. Crystalline samples of the Ir complex have a copper-like appearence. (Taken from
the cover page of Angew. Chem. Int. Ed.)
Editores / Editors: R. Burriel, C. Cativiela, L.A. Angurel, J. Chaboy, F. Lahoz
Diseño y elaboración / Design and typing: R. Burriel, C. Cativiela, L.A. Angurel y C. Marco
Impresión / Printed by: xxx
Número de ejemplares / Number of copies: 1000
2
ÍNDICE
*
ICMA: 2002-2003
*
Datos estadísticos del ICMA
*
Selección de resultados de investigación
- Ciencia y Tecnologías Químicas
- Ciencia y Tecnología de Materiales
1.- Estructura del Instituto
1.1 Organigrama
1.2 Dirección
1.3 Junta y Claustro
1.4 Departamentos de Investigación
1.5 Unidades de Apoyo
2.- Actividades
2.1 Líneas de investigación
2.1.1 Ciencia y Tecnologías Químicas
2.1.2 Ciencia y Tecnología de Materiales
2.2 Proyectos de investigación
2.2.1 Financiación europea
2.2.2 Financiación nacional
2.2.3 Financiación de las Comunidades Autónomas
2.2.4 Financiación de la industria
2.3 Divulgación científica
2.3.1 Actividades
2.3.2 Proyectos
3.- Producción científica
3.1 Artículos en revistas periódicas
3.2 Libros y obras colectivas
3.3 Tesis
3.4 Conferencias invitadas
4.- Cooperación científica
4.1 Unidades Asociadas al ICMA
4.2 Convenios con organismos extranjeros
4.3 Estancias de Investigadores en otros centros
3
CONTENTS
*
ICMA: 2002-2003
*
Statistical Data
*
Scientific Highlights
- Chemistry: Science and Technology
- Materials Science and Technology
1.- Structure of the Institute
1.1 Organizational Chart
1.2 Administration
1.3 Institute Council and Scientific Board
1.4 Research Departments
1.5 Support Services
2.- Activities
2.1 Research Areas
2.1.1 Chemistry: Science and Technology
2.1.2 Materials Science and Technology
2.2 Research Grants
2.2.1 European Funding
2.2.2 National Funding
2.2.3 Regional Funding
2.2.4 Industrial Funding
2.3 Scientific Dissemination
2.3.1 Activities
2.3.2 Grants
3.- Scientific Productivity
3.1 Journal Articles
3.2 Books and Contributions to Compiled Works
3.3 Ph.D. Theses
3.4 Invited Lectures
4.- Scientific Cooperation
4.1 ICMA Partner Laboratories
4.2 Collaborative Agreements with Foreign Institutions
4.3 Scientific Visits to Other Institutions
4
ICMA: 2002-2003
5
6
Presentación
El Instituto de Ciencia de Materiales de
Aragón (ICMA) fue creado el 24 de mayo de
1985, por un Acuerdo Específico entre el
Consejo Superior de Investigaciones Científicas
(CSIC) y la Universidad de Zaragoza (UZ), como
Centro Mixto dependiente de las dos
instituciones, acogiéndose a uno de los tipos de
colaboración establecidos por el Acuerdo Marco
entre el Consejo Superior de Investigaciones
Científicas y la Universidad de Zaragoza.
El ICMA desarrolla sus tareas de
investigación en las áreas de Ciencia y
Tecnología de Materiales (MAT) y Ciencia y
Tecnologías Químicas (QUI) y
engloba a
miembros tanto del CSIC como de la UZ, que se
encuadran en Departamentos de Investigación,
repartidos entre sus dos sedes: la Facultad de
Ciencias, sita en el campus Plaza San
Francisco, y el Centro Politécnico Superior,
ubicado en el campus Río Ebro, ambos en
Zaragoza.
Se presenta en esta memoria la actividad del
Instituto durante los años 2002 y 2003 en forma
bilingüe, castellano e inglés, para facilitar su
diseminación entre colegas de la comunidad
científica internacional.
Se ha puesto especial énfasis en describir
las líneas de investigación en las que trabajan
los distintos grupos y se han seleccionado
algunos resultados desarrollados en estas líneas
durante los dos años.
Los gráficos estadísticos ofrecidos al
principio muestran la composición del personal
del Instituto y su distribución entre las dos
instituciones y las dos áreas científicas a las que
pertenecen. Muestran también la evolución de
algunos parámetros importantes durante los
últimos diez años como son, personal, ingresos
externos, tesis y publicaciones. En los últimos
años se ha estabilizado el número de miembros
permanentes de la UZ y se ha producido un
aumento sostenido en el número de los del
CSIC. Ha habido una disminución drástica en el
número de tesis doctorales fruto del proceso
sufrido por el alumnado de los centros
universitarios relacionados con el Instituto. La
financiación ha crecido notablemente en los
últimos años y la producción científica se
mantiene en niveles cuantitativos constantes.
Durante estos dos años ha habido las
siguientes
incorporaciones
de
personal
permanente: Antonio Martín Tello, Ana Carmen
Omenat Val y Fernando Luis Vitalla como
Científicos Titulares y Concepción Marco Pérez
como Auxiliar Administrativa en comisión de
servicios. Se ha producido la baja por jubilación
de Domingo González Álvarez que fue miembro
fundador y director del Instituto durante cuatro
años y la de Berta García Landa por excedencia
voluntaria.
Los
siguientes
miembros
permanentes han tenido una promoción en su
posición: Daniel Carmona Gascón, Conrado
Rillo Millán, Pedro Algarabel Lafuente y Miguel
Angel Ciriano López a Profesores de
Investigación, José Ignacio García Laureiro y Mª
Cristina Tejel Altarriba a Investigadores
Científicos y Agustín Camón Lasheras a
Científico Titular.
El programa nacional de contratación de
investigadores postdoctorales Ramón y Cajal ha
posibilitado la incorporación de 12 doctores en
las dos convocatorias resueltas hasta finales del
2003.
Se ha iniciado la remodelación del edificio A
de la Facultad de Ciencias de la UZ que afecta a
una gran parte de los Departamentos del área
de Materiales.
En cuanto a dotación de infraestructura
científica común al Instituto se ha ampliado el
servicio de Resonancia Magnética Nuclear con
dos espectrómetros AVANCE 400 y se ha
obtenido la financiación para una plataforma de
medidas físicas PPMS de Quantum Design
destinada al servicio de medidas magnéticas.
Ha habido un aumento notable en cuanto a
la participación de la Diputación General de
Aragón en la dotación de fondos de
investigación y ha promovido la estructuración
de grupos consolidados, grupos emergentes y
grupos
de
investigación
aplicada,
proporcionando una financiación básica de
funcionamiento.
El período que abarca esta memoria queda
enmarcado por la aprobación de las normas
reguladoras de los dos organismos patronos del
Instituto, el estatuto del CSIC a finales del 2000
y los estatutos de la UZ justo al terminar 2003.
A su vez ha empezado un proceso de
generación de Institutos propios universitarios
en el que miembros del ICMA han tenido una
participación importante. Todo esto está
exigiendo replantear los modos de colaboración
entre Institutos y establecer la necesidad de una
adecuación del plan de actuación científica del
ICMA y de sus normas de funcionamiento. El
Instituto también ha participado en el plan
estratégico de la Universidad de Zaragoza con
la elaboración del suyo propio.
En mitad del período reseñado en la
Memoria se ha producido el relevo de la
dirección del Instituto y desde aquí se agradece
la constante colaboración del equipo saliente y
la disponibilidad del personal del Instituto en las
tareas
comunes
demandadas
por
las
actividades institucionales.
Ramón Burriel, Director del ICMA
7
Introduction
The Aragón Materials Science Institute was
launched as a Joint Research Center on May 24,
1985, by formal agreement between the Spanish
Council for Scientific Research (CSIC) and the
University of Zaragoza (UZ). The Institute draws
resources from, and responds to, both institutions under terms established in the 'CSIC-UZ
Framework Agreement' upon which the Institute
was founded.
The Institute conducts research in the
divisions of Materials Science and Technology
(MAT) and Chemistry: Science and Technology
(QUI) and includes both CSIC and UZ
personnel, organized into research Departments
located at two sites -- the Faculty of Sciences at
the University's Plaza San Francisco campus
and the School of Engineering at the Río Ebro
campus, both in Zaragoza.
This biennial report presents the activities of
the Institute in 2002 and 2003, in both Spanish
and English, so as to facilitate wider
dissemination among colleagues in the international scientific community.
Special emphasis has been given to
descriptions of the specific research projects
pursued by the different groups belonging to the
Institute through 2002-2003, and selected results
are presented.
The graphics presented at the beginning of
the report detail the distribution of Institute
personnel between its two parent institutions and
between its two divisions -- Chemistry and
Materials. They also show the evolution of some
important parameters over the last ten years,
such as the number of scientists, external
funding, number of Ph.D. theses presented and
publications. The last few years have seen a
levellng off of the number of permanent UZ
personnel in the Institute and a steady increase
in the number of CSIC scientists; there has
been, in addition, a drastic decrease in the
number of Ph.D. theses, reflecting a similar trend
in the undergraduate student body as it relates
to departments associated with the Institute.
Funding has increased considerably in the past
few years, and scientific productivity has been
maintained at a constant quantitative level.
In the two years covered by this report, new
permanent personnel entered the Institute -Antonio Martín Tello, Ana Carmen Omenat Val
and Fernando Luis Vitalla as Tenured Scientists
and Concepción Marco Pérez as Administrative
Assistant on secondment. Founding member
and former Director of the Institute, Domingo
González Álvarez, retired and Berta García
Landa took voluntary leave of absence. The
following Institute members were promoted -Daniel Carmona Gascón, Conrado Rillo Millán,
Pedro Algarabel Lafuente and Miguel Angel
Ciriano López to Research Professors, José
Ignacio García Laureiro and Mª Cristina Tejel
Altarriba to Research Scientists, and Agustín
Camón Lasheras to Tenured Scientist.
The national 'Ramón y Cajal' program for
hiring postdoctoral fellows made possible the
incorporation of 12 new doctoral level scientists
by the end of 2003.
Remodeling began on Building A of the
Faculty of Sciences, affecting most of the
Departments in the Materials division.
Funding for capital equipment for the
common support services of the Institute led to
expansion the Nuclear Magnetic Resonance
service with two ADVANCE 400 spectrometers.
In addition, funding has been obtained for a
Quantum Design PPMS physical measurements
platform for the Magnetic Measurements service.
There has been a substantial increase in
research support from the regional government
of
Aragón,
which
formally
recognized
consolidated research groups, emerging groups
and applied research groups, providing basic
working funding.
The period of this report is bounded by the
approval of regulations governing both of the
Institute's parent organizations -- the statute of
the CSIC at the end of 2000 and the statutes of
the UZ at the end of 2003. Moreover, the
establishment of University Institutes was
initiated during this period, with significant
participation by members of ICMA. All of this
necessitated
a
reconsideration
of
the
collaborative relationships among Institutes and
a renovation of the scientific program and
operating procedures of ICMA. The Institute also
contributed its own strategic framework plan to
that developed at the same time by the
University of Zaragoza.
The Institute underwent a change of
administration in the middle of the period
covered by this report. We thank the previous
administrative
team
for
their
ongoing
collaboration, and we are grateful to all of the
Institute personnel who contribute voluntarily to
the realization of the common tasks demanded
by institutional activities.
Ramón Burriel, Director of ICMA
8
Datos Estadísticos del ICMA
ICMA Statistical Data
9
PERSONAL
PERSONNEL
Distribución de personal a 31 de diciembre de 2003
Personnel distribution as of December 31, 2003
Personal Funcionario
Permanent Staff
125
Consejo Superior de Investigaciones Científicas
Spanish Council for Scientific Research
Profesores de Investigación
Research Professors
Investigadores Científicos
Research Scientists
Científicos Titulares
Tenured Scientists
Personal Administrativo
Administrative Personnel
Personal Técnico
Technical Personnel
53
11
8
22
4
8
Universidad de Zaragoza
University of Zaragoza
Catedráticos de Universidad
Full Professors
Titulares de Universidad
Assistant Professors
Catedráticos de Escuela Universitaria
Professors of College
Titulares de Escuela Universitaria
College Assistant Professors
72
14
46
1
11
Personal contratado y becarios
Contract Personnel and Students
Contratados postdoctorales
Postdoctoral Researchers
Profesores contratados
Non-Tenured Faculty
Becarios
Ph.D. Students
Investigadores contratados
Research Fellows
Técnicos contratados
Technical Engineers
126
17
15
76
6
12
10
CSIC
Materiales
41
72
51
62
UZ
Química
Personal científico permanente
Scientific Staff
Química
Química
16
25
35
37
Materiales
Personal permanente CSIC
CSIC Scientific Staff
Química
Materiales
Personal permanente UZ
UZ Scientific Staff
Química
41
7
35
Materiales
Becarios
Ph.D. Students
10
Materiales
Contratados postdoctorales RyC e I3P
Postdoctoral Contracts RyC and I3P
11
80
CSIC
70
UZ
60
50
40
30
20
10
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
0
Evolución del número de científicos permanentes
Evolution of the Number of Staff Scientists
12
FINANCIACIÓN
FUNDING
Financiación del ICMA, indicando el organismo por la que se ha gestionado
Funding of ICMA, according to administrating entity
3,5
Materiales
Química
Total
3,0
Millones de euros
2,5
2,0
1,5
1,0
0,5
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
0,0
Año
Recursos externos generados en las dos áreas del ICMA
External funding generated by the two divisions of the Institute
13
Financiación del ICMA (en euros) clasificada por origen y organismo gestor
Funding of ICMA (Euros) clasified by source and managing entity
AÑO
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
Gestionado por CSIC
Presupuesto ordinario
32.571
34.616
34.616
34.490
40.719
63.341
66.397
62.393
76.442
78.813
468.008
637.602
550.383
326.085
246.968
708.260
457.260
551.271
695.498
759.994
UE
99.552
130.257
111.193
35.418
50.359
30.184
34.608
109.009
148.817
60.436
Contratos y convenios
10.746
15.626
26.320
39.191
21.695
90.000
22.353
Otros
33.002
19.335
32.874
22.327
166.250
47.948
129.811
Nacional
16.233
Dotaciones extraordinarias
106.980
48.195
Total CSIC
750.859
866.903
10.476
9.039
22.694
42.005
26.259
273.479
448.307
217.446
433.926
706.668
393.237
415.012
887.238
893.262
1.358.925
1.276.151
1.485.333
Gestionado por Universidad de Zaragoza
Nacional
368.090
371.546
461.397
594.317
640.396
396.668
678.131
682.823
910.962
1.463.585
UE
124.217
31.715
221.052
180.304
281.694
140.086
246.112
157.597
321.566
461.386
Contratos y convenios
248.134
297.297
393.453
409.187
20.951
41.630
62.211
81.437
28.896
362.137
33.002
19.178
10.476
14.869
26.817
59.760
105.359
215.864
7.754
32.894
7.813
3.606
773.443
719.736
1.086.378 1.198.677
977.671
641.750
1.091.813
1.137.721
1.269.178
2.320.002
Otros
Dotaciones extraordinarias
Total UZ
Total ICMA
Presupuesto ordinario
Nacional
32.571
34.616
34.616
34.490
40.719
63.341
66.397
62.393
76.442
78.813
836.098
1.009.148
1.011.780
920.402
887.364
1.104.928
1.135.391
1.234.094
1.606.460
2.223.579
UE
223.769
161.972
332.245
215.722
332.053
170.270
280.720
266.606
470.383
521.822
Contratos y convenios
258.880
297.297
393.453
409.187
36.577
67.950
101.402
103.132
118.896
384.490
20.952
23.908
46.152
92.634
127.686
382.114
55.702
162.705
22.694
49.818
29.865
273.479
448.307
217.446
888.945
1.793.046 1.626.403 1.392.683
1.528.988
1.985.075
2.496.646
2.545.329
3.805.335
Otros
Dotaciones extraordinarias
TOTAL
66.004
35.411
106.980
48.195
1.524.302
1.586.639
% gestionado por CSIC
42,3
54,6
39,4
26,3
29,8
58,0
45,0
54,4
50,1
39,0
% gestionado por UZ
57,7
45,4
60,6
73,7
70,2
42,0
55,0
45,6
49,9
61,0
14
Recursos externos correspondientes al área de Ciencia y Tecnologías Químicas (en euros) clasificados por origen y organismo gestor
External funding (Euros) generated by the Chemistry: Science and Technology division, clasified by source and managing entity
AÑO
1994
1995
1996
1997
1998
1999
207.830
342.174
236.859
173.212
99.828
56.808
115.677
107.888
35.418
4.958
12.201
6.076
4.670
1.743
3.312
4.837
276.838
463.927
349.416
210.372
108.098
94.195
131.622
236.198
217.687
280.072
166.480
31.421
17.111
19.773
12.573
25.363
2000
2001
154.093
176.252
2002
2003
Gestionado por CSIC
Nacional
UE
89.358
Contratos y convenios
Otros
TOTAL
197.718
201.085
8.655
1.154
1.785
6.929
17.079
40.715
154.093
191.836
215.951
243.585
223.577
292.392
480.434
659.630
60.000
60.000
6.000
8.300
Gestionado por Univ. Zaragoza
Nacional
UE
Contratos y convenios
96.000
6.010
Otros
2.945
TOTAL
290.589
237.460
24.040
79.311
5.830
7.483
26.887
83.033
49.614
296.419
300.127
218.730
426.650
421.317
546.434
744.430
255.839
377.670
468.645
678.152
860.715
25.363
24.040
169.053
256.254
339.452
578.372
454.545
463.801
88.229
132.788
127.661
35.418
16.500
TOTAL ÁREA DE CIENCIA Y TECNOLOGÍAS QUÍMICAS
Nacional
UE
Contratos y convenios
Otros
6.010
379.900
4.958
12.573
96.000
87.965
60.000
60.000
7.154
10.085
12.201
9.021
4.670
7.573
10.794
31.724
83.033
56.543
17.079
57.215
445.891
720.181
586.876
506.791
408.225
312.925
580.743
613.153
762.385
988.015
% gestionado por CSIC
62,1
64,4
59,5
41,5
26,5
30,1
26,5
31,3
28,3
24,7
% gestionado por UZ
37,9
35,6
40,5
58,5
73,5
69,9
73,5
68,7
71,7
75,3
TOTAL
15
Recursos externos correspondientes al área de Ciencia y Tecnología de Materiales (en euros) clasificados por origen y organismo gestor
Project funding (Euros) generated by the Materials Science and Technology division clasified by source and managing entity
AÑO
1994
1995
1996
1997
1998
1999
2000
260.178
295.427
313.524
UE
42.744
14.581
3.306
Contratos y convenios
10.746
Otros
20.801
10.157
5.806
7.296
334.469
320.165
322.635
160.170
224.190
236.468
135.348
243.710
303.727
2001
2002
2003
147.140
618.902
303.167
375.018
497.780
558.909
45.400
30.184
34.608
109.009
148.817
60.436
15.626
26.320
39.191
13.040
88.846
20.568
16.023
28.037
22.327
159.321
30.869
89.096
703.443
399.293
656.390
766.312
729.009
360.325
230.188
454.554
390.431
430.528
803.955
Gestionado por CSIC
Nacional
TOTAL
152.873
Gestionado por Univ. Zaragoza
Nacional
UE
Contratos y convenios
Otros
TOTAL
92.796
14.605
201.279
180.304
281.694
140.086
150.112
157.597
261.566
401.386
242.124
297.297
393.453
409.187
8.378
16.267
38.171
2.126
22.896
353.837
7.754
16.394
33.002
16.233
10.476
9.039
19.335
32.874
22.327
166.250
604.390
463.483
848.918
902.257
669.732
419.415
665.164
716.405
722.744 1.575.572
TOTAL ÁREA DE CIENCIA Y TECNOLOGÍA DE MATERIALES
Nacional
496.646
430.775
557.234
456.601
507.465
849.090
757.722
765.449
928.308 1.362.864
UE
135.540
29.185
204.585
180.304
327.095
170.270
184.719
266.606
410.383
461.822
Contratos y convenios
252.870
297.297
393.453
409.187
24.004
42.587
77.362
15.167
111.742
374.405
26.390
16.281
16.336
35.358
60.910
44.654
325.572
38.623
105.490
Otros
53.803
TOTAL
938.859
783.648 1.171.553 1.062.427
893.921 1.122.858 1.064.457 1.372.794
1.489.056 2.304.581
% gestionado por CSIC
35,6
41,1
27,6
14,0
24,1
62,1
36,6
51,7
51,5
31,6
% gestionado por UZ
64,4
58,9
72,4
86,0
75,9
37,9
63,4
48,3
48,.5
68,4
16
PRODUCCIÓN CIENTÍFICA
SCIENTIFIC PRODUCTIVITY
2002
Artículos publicados en revistas científicas ordenadas por su factor de impacto
Number of scientifc papers published in each journal arranged by impact factor (SCI)
F. Impacto
Impact
factor
Artículos
Articles
26,682
7,671
7,323
6,201
4,614
4,207
4,038
3,967
3,751
3,715
3,611
3,327
3,217
3,215
3,104
3,023
2,991
2,950
2,765
2,683
2,526
2,420
2,360
2,357
2,281
2,231
2,203
2,195
2,163
2,138
2,060
2,051
1,965
1,915
1,901
1,838
1,796
1,775
1,741
1,691
1,671
1,667
1,597
1,575
1,566
1,529
1,443
1
1
3
3
5
4
6
1
1
1
3
20
2
20
1
6
1
6
2
5
6
5
3
4
6
4
1
1
3
3
1
1
1
1
5
1
2
5
1
1
2
1
3
1
1
1
2
Revista
Journal
Science
Angew. Chem. Int. Ed.
Phys. Rev. Lett.
J. Am. Chem. Soc.
Chem. Eur. J.
Appl. Phys. Lett.
Chem. Commun.
Chem. Mater.
Macromolecules
Org. Lett.
J. Phys. Chem. B
Phys. Rev. B
J. Org. Chem.
Organometallics
Acta Mater.
J. Chem. Soc. Dalton
Adv. Synth. Catal.
Inorg. Chem.
J. Phys. Chem. A
J. Mater. Chem.
Eur. J. Inorg. Chem.
Tetrahedron
Europhys. Lett.
Tetrahedron Lett.
J. Appl. Phys.
Appl. Phys. A: Mater
Chem. Phys.
Eur. J. Org. Chem.
Tetrahedron: Asymmetry
Supercond. Sci. Technol.
New J. Chem.
Bioorg. Chem. Med. Lett.
J. Membrane Sci.
Appl. Catal. A: Gen.
J. Organomet. Chem.
Phys. Chem. Chem. Phys.
J. Am. Ceram. Soc.
J. Phys. Condens. Mat.
Eur. Phys. J. B
J. Pept. Sci.
J. Solid. Stat. Chem.
Solid State Sci.
Liq. Cryst.
Chirality
Inorg. Chim. Acta
J. Cryst. Growth
Thin Solid Films
F. Impacto
Impact
factor
Artículos
Articles
1,435
1,414
1,359
1,335
1,306
1,260
1,219
1,142
1,140
1,046
1,016
1,014
0,950
0,940
0,912
0,892
0,885
0,808
0,764
0,697
0,658
0,613
0,609
0,604
0,537
0,459
0,414
0,408
0,345
0,155
-
1
1
1
1
1
1
1
2
1
14
2
1
1
2
3
1
1
1
1
2
1
1
5
3
1
1
1
4
1
2
2
1
2
1
1
1
5
1
2
1
1
1
Revista
Journal
J. Non-Cryst. Solids
Polyhedron
Inorg. Chem. Commun
Eur. J. Mineral.
Phys. Chem. Miner.
Can. J. Chem.
Metall. Mater. Trans. A
J. Eur. Ceram. Soc.
J. Phys. Chem. Solids
J. Magn. Magn. Mater.
IEEE T. Magn.
J. Alloy Comp.
Comput. Mech.
Surf. Rev. Lett.
Physica C
Mater. Lett.
J. Synchrotron Radiat.
Int. Appl. Mech.
Cement Concret. Res.
Phase Transit.
Desalination
Mater. Sci. Forum
Physica B
Int. J. Mod. Phys. B
Bio-Med. Mater. Eng.
J. Eng. Mat-T. Asme
High Pressure Res.
Ferroelectrics
Acta Phys. Pol. A
Afinidad
Abstr. Papers Am. Chem.
Acros. Org. Act.
Acta Crystallogr. E
An. Quim.
Appl. Mech. Rev.
Ceramic Engineering
CIT
Cryst. Eng. Comm.
Inorg. Synth.
Investigación y Ciencia
Prop. Solid Mech.
Rev. TdD
236
17
2003
Artículos publicados en revistas científicas ordenadas por su factor de impacto
Number of scientifc papers published in each journal arranged by impact factor (SCI)
F. Impacto
Impact
factor
Artículos
Papers
Revista
Journal
F. Impacto
Impact
factor
Artículos
Papers
Revista
Journal
8,427
7,305
7,035
6,516
5,951
4,614
4,374
4,092
4,049
4,031
3,783
3,679
3,643
3,621
3.539
3,389
3,375
3,297
3,276
3,023
2,962
2,950
2,825
2,820
2,789
2,741
2,733
2,641
2,640
2,482
2,340
2,326
2,304
2,264
2,227
2,202
2,182
2,178
2,171
2,075
2,074
2,042
1,885
1,849
1,799
1,757
1,693
3
2
8
8
1
7
3
4
3
1
1
1
1
1
1
7
17
2
1
7
15
1
1
1
2
1
1
2
1
4
1
3
1
1
2
2
1
9
8
1
1
3
3
1
2
2
1
Angew. Chem. Int. Ed.
Adv. Mater.
Phys. Rev. Lett.
J. Am. Chem. Soc.
Coord. Chem. Rev.
Chem. Eur. J.
Chem. Mater.
Org. Lett.
Appl. Phys. Lett.
Chem. Commun.
Adv. Synth. Catal.
J. Phys. Chem. B
Acta Crystallogr. B
Macromolecules
Trac-Trend Anal. Chem.
Inorg. Chem.
Organometallics
J. Org. Chem.
J. Catal.
J. Chem. Soc. Dalton
Phys. Rev. B
J. Chem. Phys.
Appl. Catal. A: Gen.
Green Chem.
Rapid.Commum. Mass Spectron.
Synlett
Biopolymers
Tetrahedron
Curr. Op. Sold. Stat. Mat. Sci.
Eur. J. Inorg. Chem.
Polymer
Tetrahedron Lett.
Nanotechnology
J. Mol. Catal. A.Chem.
Eur. J. Org. Chem.
Phys. Rev. E
Bioorg. Chem. Med. Lett.
Tetrahedron: Asymmetry
J. Appl. Phys.
Europhys. Lett.
Synthesis
J. Organomet. Chem.
Gold Bull.
Nucleos. Nucleot. Nucl.
Chaos
J. Phys. Condens. Mat.
Photoch. Photobio. Sci.
1,693
1,584
1,581
1,578
1,285
1,223
1,192
1,171
1,158
1,144
1,080
1,070
1,041
1,026
0,983
0,958
0,956
0,930
0,910
0,908
0,853
0,840
0,746
0,703
0,641
0,518
0,492
0,472
0,440
0,319
0,246
0,208
-
3
6
1
11
1
3
3
1
3
1
2
1
1
1
1
1
1
1
3
2
1
1
1
2
1
2
1
1
1
2
1
5
1
1
1
1
2
1
1
6
1
1
1
1
1
1
J. Photoch. Photobio.
Polyhedron
Catal. Lett.
Inorg. Chim. Acta
Metall. Mater. Trans. A
IEEE T. Appl. Supercon.
Physica C
J. Low Temp. Phys.
Liq. Cryst.
J. Synchrotron Radiat.
J. Alloy Comp.
Mat. Sci. Eng. B-Solid.
Nucl. Instrum. Meth. B
J. Phys. Chem. Solids
Metrología
Prog. Org. Coat.
Thermochim. Acta
Physica E
J. Magn. Magn. Mater.
Physica B
Synth. Commun.
Transit. Metal. Chem.
Phys. Solid. State
IEEE T. Instrum. Meas.
Cement Concret. Res.
Cr. Chim.
Indian J. Chem. A
Syn. React. Inorg. Mat.
Hyperfine Interact.
J. Phys. IV
Bol. Soc. Esp. Ceram. V
Acta Crystallogr. C
Anal. Bional. Chem.
Anal. Quim.
Adv. Sci. Tech.
Ceramic Engineering
Comput. Plast.
Corrosión y Protección
Ingeniería Naval
Materiales Compuestos
Org. Biomol. Chem.
Photonics and Nanoestructures
Phys. Chem. News
Recent. Res. Devel. Mat. Sci.
Rev. Esp. Física
Wind Energy
236
18
Evolución del número de publicaciones entre los años 1994 y 2003
Evolution of the number of articles from 1994 to 2003
25
20
15
10
5
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
0
Evolución del número de tesis doctorales presentadas entre los años 1994 y 2003
Evolution of the number of Ph.D. Theses from 1994 to 2003
19
Selección de Resultados de Investigación
Scientific Highlights
21
Izquierda: Micrografía con microscopía electrónica de barrido de una sección transversal de una barra
del eutéctico Al2O3-YAG obtenida por fusión zonal inducida con láser a 350 mm/h. La fase clara es
YAG y la fase oscura α-Al2O3.
Left: SEM micrograph of a transverse section of Al2O3-YAG eutectic grown at 350 mm/h using a Laser
Floating Zone technique. The bright phase is YAG and the dark phase α-Al2O3.
Derecha: Disco que contiene una suspensión del compuesto [(C6F5)2Au{µ-Ag(OClO3)}Au(C6F5)2] bajo
luz ultravioleta. El borde del disco está enfriado con nitrógeno líquido a una temperatura cercana a 77 K
y el centro se encuentra a temperatura ambiente
Right: A disc containing a suspension of the complex [(C6F5)2Au{µ-Ag(OClO3)}Au(C6F5)2] (solid) under
ultraviolet light. The border of the disc is cooled with liquid nitrogen to a temperature close to 77 K and
the centre of the disc is at room temperature.
22
Ciencia y Tecnologías Químicas
Chemistry: Science and Technology
23
−
Transition – metal allenylidene complexes can become tools for organic
synthesis more important than the carbene compounds of type LnM=CR2.
M. L. Buil, M. A. Esteruelas, A. M. López, E. Oñate.
−
A bicyclic analogue of proline stabilises the βl-turn peptide conformation.
A. M. Gil, E. Buñuel, A. I. Jiménez, C. Cativiela.
−
Nucleoside analogues: future of chemotherapeutic agents.
P. Merino, T. Tejero, F. L. Merchán, S. Franco, P. Romero, J. A. Matés, V. Mannucci.
− “Greening” the chemistry through catalysis.
J. M. Fraile, J. I. García, J. A. Mayoral.
−
C-H activation/functionalization sequences in diiridium complexes.
E. Sola, M. V. Jiménez, Y. Yuan, F. J. Lahoz, L. A. Oro.
−
Discrete mixed-valence iridium chains.
C. Tejel, M. A. Ciriano, B. E. Villarroya, J. A. López, F. J. Lahoz, L. A. Oro.
−
Vapochromic complexes.
E. J. Fernández, J. M. López de Luzuriaga, M. Monge, M. E. Olmos, J. Pérez, A.
Laguna.
24
TRANSITION – METAL ALLENYLIDENE COMPLEXES CAN BECOME TOOLS FOR
ORGANIC SYNTHESIS MORE IMPORTANT THAN THE CARBENE COMPOUNDS OF TYPE
LnM=CR2
M. L. Buil, M. Á. Esteruelas, A. M. López, E. Oñate
The hydroamination of alkynes in the
presence of transition metal complexes is an
attractive route to prepare numerous classes of
1
Two
basic
organonitrogen
molecules .
approaches have been employed to effect
aminations and involve either alkyne or amine
activation routes. Alkyne activation is generally
accomplished with late transition-metals, which
render π-alkyne intermediates. The coordination
of the alkyne to the metallic center enhances its
electrophilic character, making the alkyne
susceptible of undergoing the direct nucleophilic
2
addition of the amine .
The
evidence
that
vinylidene-metal
intermediates, LnM=C=CHR, are easily formed
from terminal alkynes and transition metals,
brings along an alternative alkyne activation
route. The reactivity of the vinylidene-metal
moiety is dominated by the electrophilicity and
nucleophilicity of the Cα and Cβ atoms,
3
respectively . As a result, one of the N-H bonds
of primary amines adds across the highly
polarized Cα-Cβ double bond of the vinylidene to
afford "aminocarbene derivatives" 4.
Allenylidene compounds LnM=C=C=CR2,
which belong to the series of unsaturated
carbene derivatives LnM=C(=C)mCR2 (m>0), has
been much less studied than the vinylidene
complexes. EHT-MO calculations indicate that
the carbon atoms of the unsaturated chain of the
allenylidene are alternatively electron-poor and
electron-rich, starting from the metal center 5.
Hence, electrophilic centers are located at the
Cα and the Cγ atoms, while the Cβ atom is a
nucleophilic site.
The coordination of the π-acidic carbonyl
group to the metallic fragment containing the
allenylidene ligand enhances the reactivity
associated with the allenylidene spine. Thus, we
have recently shown that the allenylidene ligand
5
of the complex [Ru(η -C5H5)(=C=C=CPh2)(CO)i
(P Pr3)]BF4 (1) reacts with propargylamines and
diallylamine to afford heterocyclic compounds,
which are the result of the addition of the
nitrogen atom of the amine to the Cα atom of the
allenylidene and one or two C-C couplings.
Similarly to the vinylidene complexes, the CαCβ double bond of the allenylidene ligand of 1
undergoes the addition of one of the N-H bonds
of propargylamine, to give the secondary
azoniabutadienyl derivative 2 (eq. 1). Treatment
of the latter with KOH in methanol produces its
deprotonation and the formation of the bicycle
complex 3 as a result of a double C-C coupling,
the Cα and Cγ atoms of the allenylidene of 1 and
the Cβ atom of the allenylidene with the Cβ atom
of the propargylamine.
The formation of the bicycle from the
1
unsaturated η -carbon donor ligand of 2 is a
three-elemental-step reaction involving: (i)
deprotonation of the nitrogen atom, (ii) propargyl
to allene isomerization catalyzed by the solvent
(methanol), and (iii) double intramolecular C-C
coupling. The three membered ring is a result of
a novel intramolecular cyclopropanation, which
is induced by the allenic unit and it involves the
initial nucleophilic attack of the central carbon of
the unsaturated Ru-C3 chain at the central
carbon atom of the allenic unit.
1
H
N
[Ru] +
H2N
HOPh
2
- H2 O
3
Ph
N
[Ru]
Ph
(1)
Ph
[Ru] ≡ [Ru(η5-C5H5)(CO)(PiPr3)]
The propargyl-allenic isomerization involves
a 1,3-hydrogen shift within the substituent of the
amine. To block this process, we have carried
out
the
reaction
of
1
with
1,1diethylpropargylamine, which does not contain
hydrogen atoms in α-position with regard to the
nitrogen atom. In dichloromethane, the reaction
leads to the dihydropyridiniumyl derivative 4 (eq.
2). Its formation involves the selective N,Cγ
addition of the amine to the Cα-Cβ double bond
of the allenylidene ligand of 1.
Et
Ph
+
[Ru]=C=C=C
Ph
1
Et
[Ru]
H 2N
Ph
Ph
[Ru] ≡ [Ru(η -C5H5)(CO)(P Pr3)]
5
H
N + Et
i
Et
(2)
4
In contrast to 1,1-diethylpropargylamine but
in agreement with propargylamine, the N-H bond
of N-methylpropargylamine is added to the CαCβ double bond of the allenylidene ligand of 1, to
afford the tertiary azoniabutadienyl derivative 5,
which was isolated as a mixture of the isomers
5a and 5b (eq. 3). Treatment at –78ºC of
tetrahydrofuran solutions of the isomeric mixture
with sodium methoxide gives a 1:1 mixture of the
dihydronaphtopyrrolyl diastereomers 6a and 6b.
The new polycycle is the result of two
carbon-carbon couplings in 5, the Cβ atom of the
original C3 chain with the central carbon atom of
the propargyl unit and, at the same time, an
ortho carbon atom of one of the phenyl groups
with the terminal (C(sp)) atom. These couplings
can be rationalized as an intramolecular DielsAlder reaction in an allenyl-amino-diphenyallenyl
intermediate, where the Cβ-Cγ double bond and
one of the two phenyl groups of the
25
diphenylallenyl fragment act as an inner-outer
ring diene and the C=CH2 double bond of the
another allenyl fragment acts as a dienophile.
The formation of two diastereomers in the
reaction is the consequence of the chirality of
the ruthenium and the two possible approaches
of the dienophile to the diene.
N+
CH3
Ph
[Ru]
H
1
N
H
5a Ph
+
[Ru]
H
6a
(3)
+
- CH3OH
CH3
N
[Ru]
Ph
H
5b
Ph
CH3O-
CH3
N+
CH3
N
[Ru]
Ph
Ph
H
6b
[Ru] ≡ [Ru(η -C5H5)(CO)(P Pr3)]
5
i
Diallylamine, which contains C-C double
bonds instead of a C-C triple bond, reacts in a
similar manner to propargylamine and Nmethylpropargylamine. The addition of this
organic substrate to 1 leads to the tertiary Nallyl-4-azonia-1,3,6-heptatrienyl derivative 7
(eq.4), as a result of the addition of the N-H
bond of the amine to the Cα-Cβ double bond of
the allenylidene. In the presence of bases, there
are marked differences in behavior between the
previously described azonia derivatives and 7. In
contrast to the general trend, the deprotonation
of 7 does not occur at the CH=CPh2 group but at
one of the NCH2-carbon atoms. Although the
allyl units are inequivalent, the deprotonation of
both moieties is equally favored. As a result, the
treatment of 7 with sodium methoxide in
tetrahydrofuran affords a 1:1 isomeric mixture of
the ruthenapyrrolinone complex 8 and the
pyrrolinyl compound 9.
1
HN(CH2CH=CH2)
OC
O
S
8
S
N
+
Ph
N
[Ru] ≡ [Ru(η5-C5H5)(PiPr3)]
[Ru]
[Ru]
- CH3OH
7
(4)
Ph
Ph
CH3O-
Ph
+
[Ru]
OC
S
The high degree of stereocontrol in the
formation of 8 and 9 should be pointed out. As a
result of the prochirality of the NCH2 carbon
atoms, two pairs of enantiomers of each isomer
could be formed during the reaction. However,
only one pair of 8 and one pair of 9 are obtained.
This suggests that the configuration of the
ruthenium atom of 1, and therefore of 7,
determines the configuration of the asymmetric
NCH-carbon atom of the heterocyles of 8 and 9.
Complex 9 reacts with tetrafluoroboric acid to
give the cationic derivative 10 (eq. 5). The latter,
which is an isomer of 7 is the result of the
addition of the proton of the acid to the Cβ atom
of 9. In the solid state, complex 10 is stable at
room temperature. However in dichloromethane
as solvent, it evolves to afford 11. The process
involves the opening of the five-membered
hetero-ring, formally as a consequence of the
split of the CPh2-CH(vinyl) bond, along with a
proton transfer from Cβ to the terminal carbon
atom of the vinyl substituent.
9
HBF4
[Ru]
+
Ph
N
Ph
CH2Cl2
[Ru]
r.t.
10
+
Ph
N
Ph
(5)
11
[Ru] ≡ [Ru(η5-C5H5)(CO)(PiPr3)]
Today is rare to find a complete total
synthesis that does not use a transition-metalbased reaction. In this respect, carbene
complexes are one of the most useful tools. The
reactions shown here indicate that the
potentiality of the allenylidene compounds can
become greater than that of carbene complexes
of type LnM=CR2. The preparation of transitionmetal allenylidene derivatives is very easy 6, and
the presence of three reactive centers
(unsaturated C3 chain) or more (unsaturated
chain plus substituents) in the η1-carbon ligand
allows one to build, in one or two steps, organic
skeletons, which require multistep procedures in
conventional organic synthesis.
Principal publications
M. L. Buil, M. A. Esteruelas, A. M. López, E. Oñate.
Organometallics 2003, 22, 162; ibid. Organometallics
2003, 22, 5274.
Ph
N
R
Ph
9
The formation of 8 involves the deprotonation
of the allyl group disposed trans to the CH=CPh2
unit, followed by the intramolecular attack of the
deprotonated NCH-carbon atom to the carbonyl
ligand. Complex 9 is the result of the
deprotonation of the allyl group trans disposed to
the metallic center and the subsequent
intramolecular nucleophilic attack of the
deprotonated NCH-carbon atom to the CPh2carbon atom of the CH=CPh2 moiety. Both the
formation of 8 and 9 can be rationalized as
dipolar 1,5-electrocyclizations.
Acknowledgements
We are grateful for financial support from the MCYT of
Spain (Projects BQU2002-00606 and PPQ2000-0488P4-02) M.L.B. thanks the Ministerio de Ciencia y
Tecnología (CICYT) of Spain for a Ramón y Cajal
project.
References
1
I. Bytschkov, S. Doye. Eur. J. Org. Chem. 2003, 935.
2
C. G. Hartung, A. Tillack, H. Trauthwein, M. Beller. J.
Org. Chem. 2001, 66, 6339.
3
M. I. Bruce. Chem. Rev. 1991, 91, 197.
4
M. P. Gamasa, J. Gimeno, B. Martín-Vaca, J. Borge,
S. García-Granda, E. Pérez-Carreño. Organometallics
1994, 13, 4045.
5
M. A. Esteruelas, A. V. Gómez, A. M. López, J.
Modrego, E. Oñate. Organometallics 1997, 16, 5826.
6
J. P. Selegue. Organometallics 1982, 1, 217.
26
A BICYCLIC ANALOGUE OF PROLINE STABILISES THE βI-TURN PEPTIDE
CONFORMATION
A. M. Gil, E. Buñuel, A. I. Jiménez, C. Cativiela
Small and medium-sized peptides are
usually characterised by a high conformational
freedom. This flexibility precludes their use as
medicinal agents since the various conformers
available may interact with multiple receptors
and thus lead to undesired side effects.
Reduction of the peptide backbone flexibility
through the stabilisation of secondary structure
elements constitutes a major approach in the
design of therapeutically useful peptides as well
as in the investigation of structure-activity
relationships.
Among the elements of secondary structure
usually found in peptides and proteins, β-turns
are of enormous significance not only from a
structural viewpoint but also regarding biological
activity. β-Turns involve four consecutive
residues and are classified according to the
(φ,ψ) dihedral angles of the central i+1 and i+2
positions. Types I and II β-turns, which are the
most widely distributed, are characterised by all
trans peptide bonds and generally stabilised by
an intramolecular hydrogen bond between the i
and i+3 positions.
Because of its cyclic nature, proline (Pro) is
the most conformationally constrained of the
proteinogenic amino acids, and this property
makes it a key residue both in peptide
conformation and biology. The N–Cα torsion
angle (φ) in proline is intrinsically restricted to
near –60° and, accordingly, proline is most
frequently found at the i+1 position of types I and
II β-turns. In the βI-turn the ψ angle of proline
(Cα–CO torsion) lies in the –30° region, whereas
the βII-turn is characterised by ψ around 130°.
Dipeptides of L-Pro-L-Xaa sequence typically
adopt a βI-turn in low-polarity solvents but, in
general, this conformation is not retained in the
crystalline state, where the βII-turn disposition is
preferred because it allows intermolecular
1
hydrogen-bonding of the Xaa NH site .
Additionally, a phenyl substituent, which can
interact with the backbone both electronically
and sterically, has been introduced on the βcarbon.
Figure 2: Structure of the dipeptide studied, incorporating the
bicyclic analogue of L-proline in position i+1.
The norbornane proline analogue Phb7Pro
was incorporated into the PhCO-Phb7Pro-L-PheNHiPr sequence (Fig. 2) 5 following standard
methods of peptide synthesis. This dipeptide
yielded single crystals that were subjected to Xray diffraction analysis. The crystalline structure
obtained is shown in Fig. 3. The molecule is
folded in a β-turn, with an intramolecular
hydrogen bond between the benzoyl oxygen and
the isopropylamide hydrogen (N...O distance
2.89 Å, N–H...O angle 159°), and the backbone
torsion angles correspond to a type I β-turn. This
is highly remarkable since the analogous
t
dipeptide BuCO-L-Pro-L-Phe-NHMe is not able
to retain the βI-turn conformation in the solid
state, where it has been shown to accommodate
6
a βII-turn disposition . It should be emphasised
that in the crystal structure of PhCO-Phb7Pro-Li
Phe-NH Pr the phenylalanine amide proton is not
involved in any intermolecular contact, whereas
in the L-Pro-containing dipeptide this middle NH
is hydrogen-bonded to a carbonyl group of a
neighbouring molecule.
βI-turn
Phb7Pro
(φ,ψ) = (–46,–31)
Figure 1: Structure of proline (Pro) and its bicyclic analogue
studied in this work (Phb7Pro).
We have evaluated the relative stability of
the βI- and βII-turns in model peptides RCO-LPro-L-Phe-NHR' when phenylalanine was
replaced by different constrained derivatives 2-4.
Now, we have undertaken the replacement of
the proline residue in this sequence by a bicyclic
analogue of norbornane structure. In the proline
surrogate considered, that we denote as
Phb7Pro (Fig. 1), the flexibility of the pyrrolidine
ring has been frozen by connecting the α- and δcarbons
through
an
ethylene
bridge.
L-Phe
(φ,ψ) = (–73,–12)
Figure 3: X-ray diffraction structure of the PhCO-Phb7Pro-LPhe-NHiPr dipeptide, showing a βI-turn conformation with an
intramolecular i+3 to i hydrogen bond.
This result evidences that Phb7Pro exhibits a
propensity for βI-folding higher than that of
proline. Several factors can contribute to it.
27
The three amide bonds in Fig. 3 present a
trans disposition with the torsion angles ω close
to the standard ±180°. However, the nitrogen
atom in the 7-position of the norbornane moiety
exhibits a significant distortion from planarity,
lying at a distance of 0.38 Å from the plane
defined by the three carbon atoms bonded to it.
In fact, the pyramidal character of this nitrogen
has been highlighted as an intrinsic feature of
7
the tensioned 7-azanorbornane system . In the
case considered here, this out-of-plane deviation
is particularly strong, as denoted by the sum of
the valence angles around the nitrogen (339°) in
comparison to the value expected for a planar
trigonal arrangement (360°).
The marked pyramidal geometry of this
3
tertiary nitrogen confers it a pronounced sp
character and hampers delocalization of the lone
pair to the adjacent carbonyl group. As a
consequence, a significant lengthening of the N–
CO bond (1.38 Å) is observed with respect to the
standard amide value (1.33 Å). At the same
time, the higher accessibility of the lone pair
allows the nitrogen to act as a weak hydrogenbond acceptor. Thus, in the crystalline structure
shown in Fig. 3, the phenylalanine amide
hydrogen points towards the lone pair of the
pyramidalised nitrogen (H...N distance 2.59 Å,
N...N distance 2.92 Å), giving rise to an N–H...N
attractive interaction. Interestingly, an interaction
of this type has been proposed to promote the
cis-trans isomerization of the amide bond
preceding proline by stabilising the lone pair of
the pyramidalised proline nitrogen in the
8
transition state . It should be noted that ψ
values for the bicyclic proline surrogate in the
130° region (corresponding to the i+1 position of
a βII-turn) would not allow the establishment of
this N–H...N interaction. In fact, a βII-turn
disposition for this dipeptide would place the
Phb7Pro carbonyl oxygen in the neighbourhood
of the pyramidalised nitrogen lone pair, thus
introducing a repulsive interaction.
An additional factor that can contribute to the
stabilisation of the βI-turn conformation
i
encountered for PhCO-Phb7Pro-L-Phe-NH Pr is
the presence of the extra β-phenyl substituent in
the bicyclic analogue of proline. In the structure
shown in Fig. 3, this exo-oriented phenyl ring lies
in close proximity to the phenylalanine amide
hydrogen, giving rise to an attractive interaction
of the N–H...π type. Amide-aromatic interactions
have been frequently cited as stabilising factors
9
in the structure of peptides and proteins . Again,
such an interaction would not occur in a βII-turn
disposition.
Another remarkable feature in Fig. 3 is the
gauche(+)
disposition
adopted
by
the
1
phenylalanine side chain (χ = 58°). This is the
least common of the three staggered rotamers
available to this residue, because of steric
hindrance between the phenyl ring and both the
amino and carbonyl substituents. However, this
orientation allows the existence of an additional
amide-aromatic
interaction
between
the
phenylalanine amide hydrogen and phenyl side
chain.
The βI-turn conformation accommodated by
the Phb7Pro-containing dipeptide in the
crystalline state provides evidence that the extra
attractive intramolecular interactions involving
the bicyclic proline analogue and the middle
amide
hydrogen
compensate
for
the
intermolecular hydrogen bond that stabilises the
βII-turn conformation in the L-Pro-L-Phe
sequence. Proline analogues, as the one
presented here, that are able to stabilise the βIturn disposition are extremely helpful in the
design of peptide analogues with well-defined
conformational features.
Principal publication
A. M. Gil, E. Buñuel, A. I. Jiménez, C. Cativiela.
Tetrahedron Lett. 2003, 44, 5999.
Acknowledgements
Financial support was provided by MCyT (PPQ20011834 and PPQ2002-819). The Centro de Excelencia
Bruker-ICMA is gratefully acknowledged for collection
and preliminary treatment of the X-ray diffraction data.
References
1
M. Marraud, A. Aubry, Biopolymers 1996, 40, 45.
2
A. I. Jiménez, C. Cativiela, A. Aubry, M. Marraud. J.
Am. Chem. Soc. 1998, 120, 9452.
3
A. I. Jiménez, C. Cativiela, J. Gómez-Catalán, J. J.
Pérez, A. Aubry, M. París, M. Marraud, J. Am. Chem.
Soc. 2000, 122, 5811.
4
A. I. Jiménez, C. Cativiela, M. Marraud. Tetrahedron
Lett. 2000, 41, 5353.
5
A. M. Gil, E. Buñuel, P. López, C. Cativiela.
Tetrahedron Asymmetry 2004, 15, 811.
6
A. Aubry, M. T. Cung, M. Marraud. J. Am. Chem.
Soc. 1985, 107, 7640.
7
Y. Otani, O. Nagae, Y. Naruse, S. Inagaki, M. Ohno,
K. Yamaguchi, G. Yamamoto, M. Uchiyama, T.
Ohwada. J. Am. Chem. Soc. 2003, 125, 15191.
8
G. Fischer. Chem. Soc. Rev. 2000, 29, 119.
9
T. Steiner, G. Koellner. J. Mol. Biol. 2001, 305, 535.
28
NUCLEOSIDE ANALOGUES: FUTURE OF CHEMOTHERAPEUTIC AGENTS
P. Merino, T. Tejero, F. L. Merchán, S. Franco, P. Romero, J. A. Matés, V. Mannucci
Bioorganic Chemistry Research Group
In the therapy of infections caused by viruses
and also in the treatment of certain neoplastic
diseases, nucleoside analogues have emerged
as major chemotherapeutic agents. Since the
discovery that nucleoside analogues can
effectively protect cells from the lethal action of
some
viruses,
including
the
human
immunodeficiency virus (HIV), herpes simplex
virus, hepatitis C virus and cytomegalovirus,
among others, several reviews have appeared
concerning
their
synthesis,
therapeutic
applications and mechanism of action. The
majority of nucleoside analogues consist of
modifications of natural substrates in the
heterocyclic base or the sugar moiety. The
general structure of a nucleoside analogue is
well-defined by three key elements: i) the
hydroxymethyl group, which is needed for
activation through phosphorylation by kinases, ii)
the heterocyclic base, which is needed for the
recognition by the enzymes and the
complementary strand in the nucleic acid
synthesis process, and iii) the spacer, (the
furanose ring in natural compounds) which
present the two former groups in the adequate
disposition. In this respect, it is interesting to
speculate that the biological effects exhibited by
nucleoside analogues depend importantly on the
relative disposition of the hydroxy methyl group
and the base moiety.
heterocyclic
base
HO
XH
Y
spacer
n
N
Z
hydroxymethyl
group
Figure 1. General structure of a nucleoside
Due to the high specifity of 5’phosphorylating kinases only a few variations
are allowed regarding the hydroxymethyl group.
There are a vast family of compounds grouped
under the name of nucleoside antibiotics that
present complex side chains instead of the
hydroxymethyl
group.
Hydrogen
bond
interactions
of
heterocyclic
bases
are
fundamental for the biological activity of
nucleoside analogues. So, any variation of the
base
moiety
should
preserve
such
intramolecular forces. As a consequence, only
minor variations of bases are found in
biologically active nucleoside analogues. The
most notable of that sort of structural
modifications is found in C-nucleosides, in which
the typical C-N glycosidic bond has been
replaced by a non-hydrolizable C-C bond.
On the other hand, numerous variations are
possible for the spacer whilst still retaining
activity. The relative 1’,4’ disposition of the
hydroxymethyl group and the heterocyclic base
can also be modified in order to obtain the socalled isonucleosides, compounds from both Dand L- enantiomeric series that have shown
antiviral activities.
The structural modifications of the spacer
backbone also led to active compounds.
Replacement of the furanose ring by an acyclic
chain, which can adopt a conformation similar to
conventional nucleosides, gives rise to the
acyclonucleosides,
from
which
acyclovir,
gancyclovir and their prodrugs are the best
known. The furanose ring can also be replaced
by a different carbo or heterocyclic ring. The
carbocyclic analogues are also relevant
compounds. Pyranosyl nucleoside analogues
have also been proposed an alternative to
conventional nucleosides in oligonucleotide
chains. The corresponding analogues having a
four-membered ring (oxetane) instead the
conventional furanose ring have also been
considered.
Figure 2. Antiviral drugs
The interest in nucleoside analogues in which
the furanose ring is replaced by a different
heterocyclic ring (heterocyclic nucleosides) has
appeared much more recently. It is the aim of
the group of Bioorganic Chemistry to study and
develop the methodologies for the construction
of those novel nucleoside analogues.
More complex nucleosides such as polyoxins
and nikkomycins are also studied in our group.
In particular, the polyoxins are a group of
peptidyl nucleoside antibiotics produced in the
fermentation broth of Streptomyces cacaoi var
asoensis and that have been isolated and
characterized by Isono and co-workers about
thirthy years ago. In total, about fifteen
compounds having closely related structures
have been identified and designated with
alphabetical letters. Their structure showed the
presence of a unique ribofuranosyl α-amino acid
nucleoside that constitutes the common skeleton
to all of the members of the family. The
nucleoside portion that eventually bears different
pyrimidine bases is connected through amidic
bonds to an open chain polyalkoxy α-amino acid
and to an azetidine-2-carboxylic acid. This
tripeptide structure is illustrated by the first
member of the family, polyoxin A. Some
polyoxins however are simply dipeptides
29
incorporating in their structure only two of the
above amino acids. This is the case of polyoxin
J that in fact by hydrolytic degradation leads to
the polyalkoxy α-amino acid 5-O-carbamoylpolyoxamic acid and the amino acid nucleoside
thymine polyoxin C.
O
R2
R1HN
CO2R3
NH
N
O
O
HO
OH
Nikkomycins
Polyoxins
4
O
R1: H N
2
R
R1:
OH
N
OH
R2: H
X:
O
X
NH2
R2: H, CH3, CH2OH, CO2H
R4: H, OH
Me
O
O
R3: OH,
in order to improve the activity novel analogues
are needed. Due to the differences found in the
biological activities of polyoxins and nikkomycins
when measured against the enzyme (chitin
synthase) and Candida albicans in culture it is of
high interest to prepare new analogues which
could be more effective as anticandidal agents.
In this regard the Bioorganic Chemistry group of
ICMA has also been paid attention to the
synthesis of structural analogues of polyoxins
and nikkomycins.
NH2
R3: OH
N, CH
CO2H
Figure 5. Commercial sources of Polyoxins
Figure 3. General structure of Polyoxins
The original interest for polyoxins and the
closely related natural products nikkomycins and
neopolyoxins as well as their synthetic
analogues stemmed from their marked activity
against phytopathogenic fungi whereas are non
toxic to bacteria, plants, or animals. These
biological effects apparently are due to the ability
of polyoxins to inhibit the enzyme chitin synthase
and therefore to prevent the biosynthesis of
chitin, an essential component of the fungal cell
wall structure. Hence, the polyoxin complex
obtained by fermentative processes proved to be
an excellent agricultural fungicide of wide use,
particularly for the sheath blight disease of rice
plant. More recently, considerable attention to all
the above families of peptidyl nucleosides
antibiotics,
especially
nikkomycins
and
neopolyoxins has been addressed as inhibitors
of opportunistic fungal infections by Candida
albicans in immuno-compromised hosts, such as
AIDS victims and organ transplant patients.
Candida albicans
treated
untreated
Figure 4. Differences in the cell wall of “Candida Albicans”
upon treatment with polyoxins
In our laboratory is an ongoing program aimed at
demonstrating the versatility of chiral nitrones
and hydroxylamines as building blocks for the
efficient construction of biologically interesting
nitrogenated compounds. In particular, we are
interested in the synthesis of isoxazolidinyl
nucleosides, the class of nucleoside analogues
in which the furanose ring has been replaced by
an isoxazolidine ring. Our experience in organic
synthesis allows us to suggest that isoxazolidinyl
nuleoside analogues of complex nucleosides
can be synthesized by applying our nitronebased methodology. Thus our goal is to design
novel isoxazolidinyl analogues of both
conventional
nucleosides
and
complex
nucleosides including nucleoside antibiotics
such as polyoxins and nikkomycins.
Acknowledgements
We thank for their support the Ministry of Science and
Technology (MCYT, Spain) and FEDER Program
(Project CASANDRA, BQU2001-2428) and the
Government of Aragon (Project P116-2001).
References
1
P. Merino, S. Franco, F. L. Merchán, J. Revuelta, T.
Tejero. Tetrahedron Lett. 2002, 43, 459.
2
P. Merino, J. Revuelta, T. Tejero, U. Chiacchio, A.
Rescifina, A. Piperno, G. Romeo. Tetrahedron
Asymmetry 2002, 13, 167.
3
P. Merino, A. Piperno, A. Rescifina, G. Romeo, R.
Romeo, T. Tejero. Tetrahedron 2003, 59, 4733.
4
P. Merino, S. Franco, D. Lafuente, F. L. Merchán, J.
Revuelta, T. Tejero. Eur. J. Org. Chem. 2003, 2877.
5
P. Merino, T. Tejero, M. Laguna, E. Cerrada, A.
Moreno, J. A. López. Org. Biomol. Chem. 2003, 1,
2336.
6
P. Merino, S. Franco, F. L. Merchán, P. Romero, T.
Tejero, S. Uriel. Tetrahedron Asymmetry 2003, 14,
3731.
From natural sources it is only possible to isolate
typical furanose-containing compounds whereas
30
“GREENING” THE CHEMISTRY THROUGH CATALYSIS
J. M. Fraile, J. I. García, J. A. Mayoral
highly modular and are prepared
i
the silica support with Ti(O Pr)4
precursor, under soft conditions.
the support plays an important
with the titanium dispersion.
by reaction of
as a titanium
The nature of
role, together
Hydrophilic silica
O
SILICA
SILICA
OH
Ti(OiPr)4
H
OH
O
OiPr
Ti
OX
O
O
H
(X = iPr or H)
SiMe2R
SiMe2R
O
SILICA
O
SILICA
Although Chemistry is perceived as a
pollutant activity, many chemists are involved in
the development of cleaner products and
processes, which allow the sustainability and the
economical growth without compromising the
environment, in the field known as “green
chemistry”. Catalysis is probably one of the most
valuable tools for this purpose, because it allows
a better use of the starting materials (higher
conversion), lower energy consumption and a
lower waste generation due to the higher
selectivity of the process. The use of
heterogeneous catalysis results additionally
advantageous because of the easiness of
separation, recycle and reuse.
As base of this philosophy, “green chemistry”
must be economically attractive for the industry,
given that all the objectives have an impact on
lowering the costs of production. In fact, several
industries are involved in this type of research
1,2
, trying for example the substitution of strong
mineral acids, such as sulfuric or hydrochloric
acids, by solid acids which minimize the
corrosion problems, allowing at the same time
an easier storage and handling.
One of the main pollution sources in the
chemical industry is the generation of byproducts, inherent to the use of specific
reagents. One clear example is the oxidation
reactions. The use of potassium dichromate
brings inherent the production of chromium salts
and oxides. When epoxides are considered, the
most popular oxidants are peracids, such as
meta-chloroperbenzoic
acid,
but
the
corresponding acid is produced as stoichiometric
by-product. Because of that the most suitable
oxidants are molecular oxygen and hydrogen
peroxide. As oxygen usually requires a sacrificial
reductant, such as an aldehyde, hydrogen
peroxide remains as one of the most promising
alternative, given that the only by-product
generated is water. However, a catalyst is
necessary in order to activate hydrogen peroxide
and the requirements of this catalyst are quite
exigent, as it must work in the presence of
water. This is not especially difficult in the case
of electrophilic alkenes, as the activation of
hydrogen peroxide is carried out with a base 3.
Within the research line devoted to the
development of basic solid catalyst, the use of
natural phosphate from Morocco has shown a
high potential interest, due to its low cost and
4
high activity in several reactions , with the
additional
advantage
of
low
solvent
requirements.
However the epoxidation of nucleophilic alkenes
requires the activation of hydrogen peroxide with
a Lewis acid, a not easy task in the presence of
water. In contrast with previous ideas, our group
was able to activate diluted (30%) hydrogen
peroxide with easily prepared silica-supported
titanium catalysts (Figure 1). These catalysts are
Ti(OiPr)4
H
O
O
O
Ti
O
OiPr
OX
H
Hydrophobic silica
Figure 1: Synthesis of silica-supported titanium catalysts.
Additional modifications can be introduced
on the environment of titanium by substitution of
the remaining isopropoxide groups by diols,
aminoalcohols and diamines 5. The modification
of the Lewis acidity of the titanium centres, as
shown by experimental NH3 desorption and
theoretical calculations, does not only modify the
epoxidation activity, but also the selectivity to
epoxide due to changes in the hydrolysis activity
and the participation of the radical allylic
oxidation mechanism.
radical pathway
OOH
OH
+
[Ti]
2 H2O2
[Ti]
[Ti]
O
2 H2O
H2O
H2O
[Ti]
hydrolysis
H2O2
O
H2O
[Ti]
direct epoxidation
OH
OH
Figure 2: Mechanisms of epoxidation with H2O2.
In spite of all the improvements introduced
by the catalyst design, the most important step
towards the practical application of this method
is the optimization of the reaction conditions 6.
The slow addition of hydrogen peroxide
drastically reduces the rate of decomposition,
and as a consequence the molecular oxygen
concentration in the reaction medium. In this
way the radical allylic oxidation is minimized
(Figure 2) and the epoxide hydrolysis remains as
the only problem to be solved.
Methods for the characterization of the
titanium sites are currently under development,
31
together with the study of the structure-activity
relationships.
The easiness of recovery of heterogeneous
catalysts is especially interesting in the case of
high cost catalysts, as asymmetric ones. The
chiral ligands are usually expensive or even no
commercially available, and then the recycle of
the catalyst, with the improvement in
productivity, represents an important saving in
investment. The covalent grafting, which
ensures the chiral ligand recovery, is probably
the best established immobilization method for
asymmetric catalysts. The development of
methodologies for grafting of ligands of general
application are highly interesting, given that they
open the way to a large variety of chiral
catalysts.
This
is
the
case
of
pyridinebis(oxazolines), tridentate ligands able to
coordinate metals such as ruthenium, rhodium
or lanthanides. The introduction of spacers in the
position 4 of the pyridine ring (Figure 3) allows
7
and inorganic
the easy grafting on organic
supports 8. After the preliminary test on the
cyclopropanation reaction, other applications are
currently under development.
SUPPORT
O
N
R
O
N
N
R
Figure 3: Immobilization of pyridinebis(oxazoline).
In this type of immobilization, the
accessibility of the ligand is crucial for an
efficient complexation with the metal precursor.
When this complexation is difficult, an important
part of the expensive ligand remains useless.
Thus, even in the case of a high productivity per
metal site, the productivity per chiral ligand is
low, a term we called “ligand economy” 9. In this
regard, the morphology of the support plays a
decisive role. In the case of polymerized chiral
ligands, the composition of the monomeric
mixture and the polymerization solvent are the
most important factors. We demonstrated that
dendrimers can act as more efficient crosslinking agents, conferring to the polymer a more
open structure which allows a better ligand
10
economy .
In spite of the cited advantages, the covalent
grafting of chiral ligands requires a (sometimes)
hard synthetic work in the modification of the
ligand. Moreover, the functionalization of the
chiral ligand with a very bulky substituent, as it is
the solid support, leads in many cases to a
drastic reduction of the enantioselectivity. Trying
to prevent this problem, our group has been
working in the immobilization of cationic
complexes by electrostatic interactions with
anionic supports. In such case, the metal
carrying the positive charge is strongly hold by
the support, but we detected some ligand
leaching due to competitive complexation with
reaction products and by-products. This problem
is currently be solved by using analogue ligands
11
which bind more strongly the metal centre .
Although it is considered that the supportligand steric interaction is weaker in the case of
catalysts immobilized through electrostatic
interactions, this is not the case when layered
materials, such as clays, are used as supports.
The dielectric constant of the reaction solvent
modifies the relative position of the complex and
the clay surface, and hence the steric interaction
between them. Thus it is possible to design
chiral ligands specifically to be used under such
conditions, taking advantage of this interaction.
In a preliminary work this possibility has been
12
but further improvements are
demonstrated
being currently done.
In
conclusion,
the
application
of
heterogeneous catalysts to the fine chemicals
synthesis allows the development of cleaner
processes, through substitution of harmful
homogeneous acids and bases, the use of
cleaner reagents and the efficient recovery and
reuse of the catalyst. In some cases the
heterogeneous character even modifies the
selectivity of the catalyst, leading to interesting
new properties.
Acknowledgements
Financial support for this work was provided by the
Spanish CICYT (projects MAT99-1176, PPQ20000322-P4 and PPQ2002-04012) and the DGA.
References
1
C. Cativiela, J. M. Fraile, J. I. García, B. Lázaro, J. A.
Mayoral, A. Pallarés. Appl. Catal. A 2002, 224, 153.
2
C. Cativiela, J. M. Fraile, J. I. García, B. Lázaro, J. A.
Mayoral, A. Pallarés. Green Chem. 2003, 5, 275.
3
J. M. Fraile, J. I. García, J. A. Mayoral, S. Sebti, R.
Tahir. Green Chem. 2001, 3, 271.
4
S. Sebti, A. Solhy, R. Tahir, S. Abdelatif, S.
Boulaajaj, J. A. Mayoral, J. I. García, J. M. Fraile, A.
Kossir, H. Oumimoun. J. Catal. 2003, 213, 1.
5
J. M. Fraile, J. I. García, J. A. Mayoral, L. Salvatella,
E. Vispe, D. R. Brown, G. Fuller. J. Phys. Chem. B
2003, 107, 519.
6
J. M. Fraile, J. I. García, J. A. Mayoral, E. Vispe,
Appl. Catal. A 2003, 245, 363.
7
A. Cornejo, J. M. Fraile, J. I. García, E. GarcíaVerdugo, M. J. Gil, G. Legarreta, S. V. Luis, V.
Martínez-Merino, J. A. Mayoral. Org. Lett. 2002, 4,
3927.
8
A. Cornejo, J. M. Fraile, J. I. García, M. J. Gil, V.
Martínez-Merino, J. A. Mayoral. Molecular Diversity
2003, 6, 93.
9
M. I. Burguete, E. Díez-Barra, J. M. Fraile, J. I.
García, E. García-Verdugo, R. González, C. I.
Herrerías, S. V. Luis, J. A. Mayoral. Bioorg. Med.
Chem. Lett. 2002, 12, 1821.
10
E. Díez-Barra, J. M. Fraile, J. I. García, E. GarcíaVerdugo, C. I. Herrerías, S. V. Luis, J. A. Mayoral, P.
Sánchez-Verdú, J. Tolosa. Tetrahedron Asymmetry
2003, 14, 773.
11
J. M. Fraile, J. I. García, M. A. Harmer, C. I.
Herrerías, J. A. Mayoral, O. Reiser, H. Werner, J.
Mater. Chem. 2002, 12, 3290.
12
A. Cornejo, J. M. Fraile, J. I. García, M. J. Gil, C. I.
Herrerías, G. Legarreta, V. Martínez-Merino, J. A.
Mayoral. J. Mol. Catal. A 2003, 196, 101.
32
C-H ACTIVATION/FUNCTIONALIZATION SEQUENCES IN DIIRIDIUM COMPLEXES
E. Sola, M. V. Jiménez, Y. Yuan, F. J. Lahoz, L. A. Oro
“What one metal can do,
two metals can do better”
Considering our present understanding of the
structure/reactivity relationships in di- and
polynuclear metal compounds, this sentence,
often found in articles, reviews and monographs,
should be better regarded as the formulation of a
reasonable expectation rather than as a fact.
Indeed, the chemical literature contains
several particular examples describing unusual,
sometimes extraordinary, chemical transformations which can be eventually attributed to the
presence of two or more metal atoms in close
proximity. However, references can also be
found describing polymetallic complexes that fail
to give reactions easily achievable by related
mononuclear species. This indicates that the
chemistry of polynuclear compounds should be
expected to differ from that of mononuclear
relatives, although, not surprisingly, the differences cannot always result into advantages. Due
to this, the practical exploitation of this chemistry
seems unlikely without a previous effort to
further understand the peculiar chemistry of
multimetallic sites and the mechanisms of intermetallic cooperation.
Aimed at this goal, we initiated a systematic
reactivity study of simple and NMR accessible
dinuclear compounds of iridium such as those
shown in Chart 1. Investigation of complex 1 led
to the characterization of a mechanisms for
intermetallic communication based on the
1
transmission of trans effects , which effectively
operates in fast and selective catalytic
hydrogenation cycles 2. In contrast, the study of
complex 2 and related compounds revealed the
inadequacy of such open-book dinuclear Ir(I)
compounds for simple concerted activations that
readily take place at parent mononuclear
derivatives.
pounds favors the oxidative addition of C-H
3
bonds (Chart 2) .
Chart 2: Alkene C-H activations at dinuclear complexes can be
promoted by oxidation.
The rationalization of this fact and other complementary results in the frame of the molecular
orbital description of such dinuclear Ir(I)
compounds concluded that the simplest requirement to get C-H activating compounds is the
breaking of their symmetry, since such operation
is enough to liberate an empty orbital from the
weak, but highly deactivating, metal-metal
interactions existing in these compounds 4.
A straightforward application of this conclusion has involved the use of bridging ligands that
can asymmetrically coordinate the diiridium
moiety. As can be seen in Chart 3, the asymmetric arrangement of such ligands led to
complexes promoting C-H activation / insertion
sequences of ethylene.
Chart 3. Asymmetric bridging systems promote C-H activation
/ insertion reaction sequences with ethylene.
The generalization and further development
of this strategy to achieve other reaction
sequences in route to catalytic functionalization
processes in under current investigation.
Principal publication
Y. Yuan, M. V. Jiménez, E. Sola, F. J. Lahoz, L. A.
Oro. J. Am. Chem. Soc. 2002, 124, 752.
Chart 1. Dinuclear iridium complexes typically used along this
investigation.
Acknowledgements
“Catálisis homogénea por complejos de metales de
transición” (BQU2000-1170).
Due to our interest in C-H activations of
potential use for small molecule functionalization, we explored possible strategies to overcome the inertness of these Ir(I) dinuclear
compounds toward concerted C-H oxidative
additions. The rich chemistry of these complexes
provided several successful ways by which their
activation capability could be experimentally
enhanced. In particular, we did the very counterintuitive observation that oxidation of the com-
References
1
E. Sola, F. Torres, M. V. Jiménez, J. A. López, S. E.
Ruíz, F. J. Lahoz, A. Elduque, L. A. Oro. J. Am. Chem.
Soc. 2001, 123, 11925.
2
F. Torres, E. Sola, A. Elduque, A. P. Martínez, F. J.
Lahoz, L. A. Oro. Chem. Eur. J. 2000, 6, 2120.
3
M. V. Jiménez, E. Sola, J. Caballero, F. J. Lahoz, L.
A. Oro. C. Angew. Chem. Int. Ed. 2002, 41, 1208.
4
L. A. Oro, E. Sola in Recent Advances in Hydride
Chemistry, M. Peruzzini, R. Poli (Eds.), Elsevier, 2001,
p. 299.
33
DISCRETE MIXED-VALENCE IRIDIUM CHAINS
C. Tejel, M. A. Ciriano, B. E. Villarroya, J. A. López, F. J. Lahoz, L. A. Oro
Compounds containing discrete chains of
metal-bonded atoms are highly interesting not
only from a theoretical point of view, but also
because of their potential applications,
particularly as candidates for nanoscale
electronic devices. Reproducible and welldefined syntheses for these compounds include
ligand-assisted reactions of metal compounds
with conjugated polyenes 1 and with polydentate
2
ligands, such as oligo-α-pyridylamino ligands .
In these cases, the number of available
coordination sites of the ligand determines the
length of the metallic chain.
Our approach to the synthesis of discrete
metal-chains of iridium, which are mostly
unknown 3, is different from the above described
systems. It involves the oxidation of dinuclear
8
complexes of d square-planar metal centers to
form metal-metal bonds between two dinuclear
units, which leads to a spontaneous linear
condensation. This methodology has, in
principle, no other limitations on the growing of
the
metallic
chain
length
than
the
thermodynamic stability of the products,
provided that the steric encumbrance between
the links is kept at minimal.
We have found that the binuclear complex
[Ir2(µ-Opy)2(CO)4] (Opy = 2-pyridonate) is an
appropriate precursor for discrete iridium chains.
Thus, oxidation of [Ir2(µ-Opy)2(CO)4] with
diiodine gave the unsymmetrical tetrametallic
chain (HT,HH)-[Ir4(µ-Opy)4(I)2(CO)8][3] formed by
a linear stack of HT-[Ir2(µ-Opy)2(I)(CO)4] and
HH-[Ir2(µ-Opy)2(I)(CO)4] units with an fractional
averaged oxidation state (+1.50) for the iridium
atoms, as shown in Chart 1.
O
N
Ir
I
OC
C
O
N
O
Ir
OC
C
O
O
C CO
Ir
I
O
C CO
Ir
O
O
N
N
(HT,HH)-[Ir(+1.5)4]
Chart 1. Schematic representation of (HT,HH)-[Ir4(µOpy)4(I)2(CO)8]. The Opy ligands are represented as N-C-O for
clarity.
The complex (HT,HH)-[Ir4(µ-Opy)4(CO)8] was
found to evolve to (HH,HH)-[Ir4(µ-Opy)4(CO)8] on
heating, which shows the HH,HH configuration
systematically found for the related tetranuclear
platinum chains. What is remarkable here is the
demonstration that, contrary to previous
speculations, binuclear complexes with HT
configurations are able to engage in tetrametallic
chains. Moreover, with this experimental
evidence, one can imagine the growing of
unidimensional metallic chains through HT
linkers, since they do not show steric hindrance
along the direction of the metal-metal bond,
allowing the entrance of new dinuclear units in
this axis. In fact, we were able to add a new HH
link to the tetrametallic chain (HT,HH)-[Ir4(µOpy)4(CO)8] to form the hexametallic compound
(HH,HT,HH)-[Ir6(µ-Opy)6(I)2(CO)12] by careful
oxidation of [Ir2(µ-Opy)2(CO)4] with diiodine. The
crystal structure of the new complex (Figure 1)
revealed the almost linear array of the metals in
units
which
two
HH-[Ir2(µ-Opy)2(I)(CO)4]
sandwich an HT-[Ir2(µ-Opy)2(CO)4] complex.
Figure 1. The almost linear array of metal atoms (in yellow) in
the first hexanuclear iridium-chain. This 1-D oligomer is a
molecular piece of a “metal-wire” related to the infinite mixedvalence metal chains, such as the Krogmann salts. Crystalline
samples of the Ir complex have a copper-like appearence.
(Taken from the Page Cover of Angew. Chem. Int. Ed.)
Noteworthy is also the fractional oxidation
state (+1.33) for the iridium atoms in the
hexanuclear compound, which provides a new
link in the electronic sequence connecting
dinuclear Ir(I) and Ir(II) compounds:
{Ir(+1)}2
{Ir(+1.33)} 6
{Ir(+1.5)}4
{Ir(+2)}2
Principal publication
C. Tejel, M. A. Ciriano, B. E. Villarroya, J. A. López, F.
J. Lahoz, L. A. Oro. Angew. Chem. Int. Ed. 2003, 42,
529.
Acknowledgements
“Síntesis, estructura y reactividad de complejos monoy poli-metálicos con posibles propiedades catalíticas o
conducturas” (BQU2002-00074).
References
1
T. Murahashi, T. Nagai, Y. Mino, E. Mochizuki, Y.
Kai, H. Kurosawa. J. Am. Chem. Soc. 2001, 123,
6927.
2
R. Clérac, F. A. Cotton, T. B. Dunbar, C. A. Murillo,
X. P. Wang. J. Am. Chem. Soc. 2000, 122, 2272.
3
C. Tejel, M. A. Ciriano, B. E. Villarroya, R. Gelpi, J. A.
López, F. J. Lahoz, L. A. Oro. Angew. Chem. Int. Ed.
2001, 40, 4048.
34
VAPOCHROMIC COMPLEXES
E. J. Fernández, J. M. López de Luzuriaga, M. Monge, M. E. Olmos, J. Pérez, A. Laguna
Closed-shell interactions occur mainly for
some heavy late transition metals and maingroup elements. In fact, these are dispersion
forces reinforced by relativistic effects and by
ionic components, of which the former are
maximized
in
heteronuclear
interactions.
Heteronuclear compounds containing gold(I) and
10 10
group-11, -12, and -13 metals display d -d or
10 2
d -s closed-shell interactions of intermediate
strength relative to the homonuclear metal-metal
interactions. The number of examples of gold(I)gold(I) contacts is large, but representatives of
heteronuclear gold(I)-metal contacts are still
scarce. There are two general types of
derivatives displaying short gold-metal distances
-those with bridging ligands and those that are
unbridged, of which the latter are always the
more indicative of the presence of a real bond.
Derivatives featuring unsupported gold-metal
bonds have been obtained mainly through
reactions between basic gold(I) complexes and
acid complexes, and also by encapsulation of
metal centers in metallocryptands. Most
derivatives with supported gold-metal bonds
have been synthesized by use of C-donor
ligands or ambidentate ligands. The gold-metal
contacts dramatically affect the conformations
and the aggregation of the molecules, and also
their optical properties. Some of these
1
derivatives are, in fact, intensely luminescent .
changes from red (near 77 K), through orange
and yellow, to green (room temperature) 2.
The complex {Tl[Au(C6Cl5)2]}n, displays a
vapochromic behavior with reversible color
changes when the solid is exposed to a variety
of organic vapors. Acetone, acetonitrile, triethylamine,
acetylacetone,
tetrahydrothiophene
(THT), 2-fluoropyridine, tetrahydrofuran (THF),
and pyridine vapors (see Figure 2) have been
used. The color changes back to that of the
starting material upon heating to 100 °C over a
period that requires from a few seconds for
acetone to 10 min for pyridine. In all cases, the
process is found to be completely reversible with
no detectable degradation of the starting
material after 10 exposure/heating cycles. The
exchange of color is even deeper under UV light,
and the substances display a strong
luminescence under these conditions.
Figure 2. Powder samples of {Tl[Au(C6Cl5)2]}n, deposited on
filter paper and exposed to selected organic vapors: (1) 2flouropyridine, (2) THF, (3) acetone, (4) acetylacetone, (5)
acetonitrile, (6) pyridine, (7) triethylamine, (8) THT.
Principal publication
E. J. Fernández, J. M. López de Luzuriaga, M. Monge,
M. E. Olmos. J. Pérez, A. Laguna, A. A. Mohamed, J.
P. Fackler. J. Am. Chem. Soc. 2003, 125, 2022.
Acknowledgements
This work was supported by the Dirección General de
Investigación (BQU2001-2409).
The picture shows a disc that contains a
suspension of the complex [(C6F5)2Au{µAg(OClO3)}Au(C6F5)2] (solid) under ultraviolet
light. The border of the disc is cooled with liquid
nitrogen to a temperature close to 77 K and the
centre of the disc is at room temperature. The
luminescence and the colour of the complex
References
1
M. Bardají, A. Laguna. Eur. J. Inorg. Chem. 2003,
3069.
2
E. J. Fernández, M. C. Gimeno, A. Laguna, J. M.
López de Luzuriaga, M. Monge, P. Pyykkö, D.
Sundholm. J. Am. Chem. Soc. 2000, 122, 7287.
35
Ciencia y Tecnología de Materiales
Materials Science and Technology
37
−
Observation of discrete breathers in josephson arrays.
J. J. Mazo.
−
Lustre pottery: the secret of early nanomaterials revealed by transmission
electron microscopy.
A. Larrea, J. Pérez-Arantegui.
−
Ceramics for high temperature structural applications.
J. I. Peña, A. Larrea, R. I. Merino, I. de Francisco, P. B. Oliete, V. M. Orera.
−
Hyscore spectroscopy of the cytochrome b559 of photosystem ll reaction centre.
P. J. Alonso, J. I. Martínez.
−
Enhanced anisotropy of nanosized Co clusters: effects from surface and interparticle interactions.
F. Luis, J. M. Torres, L. M. García, J. Stankiewicz, J. Bartolomé, F. Petroff.
−
A thiazyl-based organic ferromagnet: magnetism and spin-density distribution by
polarised neutron diffraction experiments and ab initio calculations.
J. Campo, F. Palacio, J. Luzón, G. J. McIntyre, A. Alberola, J. M. Rawson, C. Paulsen,
R. D. Farley.
−
Towards the magnetic refrigeration: the magnetocaloric effect. A new method of
characterization with an adiabatic system.
R. Burriel, E. Palacios, L. Tocado.
−
Synchrotron X-ray resonant scattering in metallic oxides: charge and orbital
ordering.
J. García, G. Subías, J. Blasco, M. G. Proietti, M. C. Sánchez, J. Herrero-Martin.
−
New opportunities in trace elements structural characterization: high-energy Xray absorption near-edge structure spectroscopy.
J. Chaboy.
−
Pressure-induced three-dimensional ferromagnetic correlations in the giant
magnetocaloric compound Gd5Ge4.
C. Magen, L. Morellon, P. A. Algarabel, M. R. Ibarra.
−
Superconducting properties of metal/MgB2 composite wires.
E. Martínez, L. A. Angurel, A. Millán, R. Navarro.
−
Photo-induced chirality on achiral side chain liquid crystalline polymethacrylates
L. Oriol, M. Piñol, R. M. Tejedor, J. L. Serrano, R. Alcalá, F. J. Rodríguez, B. Villacampa
−
Chiral helical induction through H-bonding in supramoelcular polymers.
J. Barberá, L. Puig, J. L. Serrano, T. Sierra.
−
Novel NLO-phores with proaromatic donor and acceptor groups.
R. Andreu, J. Garín, J. Orduna, R. Alcalá, B. Villacampa.
−
The cryogenic current comparator, design tools for an ultimate precision
instrument.
J. Sesé, A. Camón, C. Rillo.
38
OBSERVATION OF DISCRETE BREATHERS IN JOSEPHSON ARRAYS
J. J. Mazo
Under the exotic name of discrete breathers
or intrinsic localized modes we refer to the
dynamical phenomenon of energy localization by
nonlinearity and discreteness in perfect -disorder
free- lattices. Our group at ICMA has been
pioneering in the theoretical study of such
modes. We have also carried out the theoretical
prediction and experimental detection of discrete
breathers in Josephson arrays, a type of
superconducting solid-state devices. This work
is one of the first and, to our opinion, one of the
clearest observations of discrete breathers in
any real system.
1000
990
980
970
960
25
50
75
100
Figure 1: One discrete breather (oscillobreather)
Before the discovering of discrete breathers,
the phenomenon of energy localization in
physical lattices was associated with the
existence of defects or disorder in the lattice. It
was thought that any initially localized state
would radiate energy and delocalize emitting
plane waves or phonons, the linear vibrational
modes of the lattice. However, an intense
theoretical and computational work starting in
the late 1980s showed the existence of longliving localized modes in discrete and non-linear
lattices
without
disorder.
Such
modes
correspond to – usually periodic – localized
vibrations or rotations in the lattices. Intrinsic
localized modes exist both for the case of
Hamiltonian lattices (energy is conserved) or
dissipative and biased ones (where external bias
balances the losses due to the intrinsic
dissipation). It is also important to say that,
contrary to other nonlinear excitations, discrete
breathers exist in one-, two- or three1
dimensional systems .
Figure 1 shows a numerical simulation of a
localized vibrational mode in a FrenkelKontorova chain. This system is formed by a
chain of nonlinear pendula joined by harmonic
springs and subjected to dissipation and a
periodic external force; see the small amplitude
oscillation of particles in the ends. As it can be
seen, the breather solution corresponds to a
highly localized vibration of the chain. The
particles in the core of the breather describe
large amplitude oscillations meanwhile other
particles librate with small amplitude under the
effect of the external force. From the point of
view of the theory of dynamical systems, the
solution is an attracting limit cycle, and it is
structurally stable and robust under thermal
fluctuations.
Figure 1 shows an example of a mode with
localized oscillation or oscillobreather. However,
for the case of arrays made of interacting rotors
it is possible to have also localized rotations or
rotobreathers.
After some years of intense theoretical and
numerical work; recently, most of the efforts in
this field have been focused on the experimental
detection of discrete breathers in real physical
systems. In fact, up to the date they have been
observed in solid state mixed-valence transition
metal complexes, quasi-1D antiferromagnetic
chains, superconducting arrays made of
Josephson-junctions,
micromechanical
oscillators, optical waveguide systems and 2D
1
photonic structures .
Our team of the department of Theory and
Simulation of Complex Systems at ICMA has
played a key role in the achievement of the
experimental observation of discrete breathers in
Josephson arrays.
2
In the work of 1996 it was proposed a
particular Josephson-junction configuration, the
ladder as an ideal experimental system to study
the phenomenon of intrinsic localization. There,
and in following works, the theoretical basis was
established and the existence of discrete
breathers in such arrays predicted. Based on
such theoretical studies, the experimental effort
to excite and detect localized solutions was
carried out independently by the group of Terry
3
Orlando at MIT -in close collaboration with the
author, Visiting Scholar at MIT at the time-, and
the group of Alexey Ustinov in Erlangen 4 -also
linked to our group through a common European
project-. The experiments were successfully
carried out in both laboratories. A nice brief
presentation of both works can be found in 5 and
a longer, still popularized one in 6. For more
authorized reviews, see P2 and 7.
Figure 2 shows one of the superconducting
Josephson ladders fabricated to observe
rotobreather states. The junctions are made by
Niobium superconducting islands connected by
thin Aluminium Oxide insulating barriers. The
ladder consists on two rows with 9 Niobium
islands each one, connected through a total of
25 Josephson-junctions: 9 vertical and 16
horizontal (8 in the top row and 8 in the bottom
one).
39
3,0
Total applied current (mA)
T = 5.2 K
2,5
V4 , V5, V6
V4T , V6T
Resistive branch
2,0
V5
1,5
Breather state
V4 , V6
Initial
current
V4T
V5T
1,0
0,5
0,0
V4 , V5
Multi-site
breather states
V4 , V5 , V6
Zero voltage state V4 , V5 , V6 , V4T , V5T
-1
0
1
2
3
Junction Voltage (mV)
Figure 4: The experimental detection
Figure 2: The Josephson ladder (Josephson junctions are
sketched in red at the bottom right panel)
Each junction in the ladder can be modelled
by a nonlinear rotor characterized by a phase,
an angular variable. The localized state we are
looking for is a rotobreathers: a few of the
junctions are in a resistive state (which
corresponds to a rotation of the phase) and the
others in a superconducting one (these phases
do not rotate). Figure 3 illustrates some of the
many different breather states that were
observed in Josephson ladders. There, crosses
have been used to denote resistive (rotating)
junctions and shorts for superconducting ones.
Some of them are up-down symmetric, others
not; some correspond to one-site solutions,
others to m-site ones. Figure 4 shows one of the
current-voltage curves measured in the ladder
that allowed detecting the discrete breather
solutions.
single-site
After observation in the ladder, the new
challenge of the field is the experimental
detection of a discrete breather in a twodimensional
array.
Recently,
we
have
numerically found the existence of such states,
see figure 5 for a simulation, and established the
experimental conditions for the excitation and
detection of discrete breathers in a twoP1
dimensional array . Recent experiments, not
yet published, performed by Ustinov’s group
valid this scenario.
Figure 5: Rotobreather in a 2D Josephson array
Principal publication
P1
J. J. Mazo. Phys. Rev. Lett. 2002, 89, 234101.
P2
J. J. Mazo, T. P. Orlando. Chaos 2003, 13, 733.
Acknowledgements
Financial support by DGES (PB98-1592), EU (HPRNCT-1999-00163) and MCyT (BFM2002-00113).
multi-site
multi-breathers
Figure 3: Zoo of breather excitations
References
1
D. K. Campbell et al, Physics Today 2004, 57, 43.
2
L. M. Floría, J. L. Marín, P. J. Martínez, F. Falo, S.
Aubry. Europhys. Lett. 1996, 36, 539.
3
E. Trías, J. J. Mazo, T. P. Orlando. Phys. Rev. Lett.
2000, 84, 741.
4
P. Binder et al. Phys. Rev. Lett. 2000, 84, 745.
5
L. M. Floría. Physics World 2000, 13 (4), 23.
6
L. M. Floría, J. L. Marín, J. J. Mazo. Investigación y
Ciencia, Junio 2002.
7
J. J. Mazo in “Energy localization and transfer”.
Advances Series in Nonlinear Dynamics, World
Scientific, 2004, vol 22. 193.
40
LUSTRE POTTERY: THE SECRET OF EARLY NANOMATERIALS REVEALED BY
TRANSMISSION ELECTRON MICROSCOPY
A. Larrea, J. Pérez-Arantegui
Lustre is a type of ceramic decoration, which
results in a beautiful metallic shine and coloured
iridescence on the surface of the ceramic object.
Among the different ceramic techniques often
termed as ‘lustre’, the ‘reduced-pigment lustre’
is made by applying some pigments (usually
silver and copper compounds) mixed with clay or
ochre to the surface of an already-fired glaze.
Then the ceramic piece is re-fired to a low
temperature in a reducing atmosphere. When
the piece is cool and out the kiln, the surface is
cleaned by rubbing to remove the clay that is on
the design, and lustre appears with metallic
sheen and different colours. Almost all the lustre
made before 1800 belongs to this family and it
includes all Islamic, Spanish and Italian lustre
ware.
The earliest lustre was probably made in Iraq
in the IXth century AD on tin-glazed ceramics.
Lustre technology spread from the Middle East
to Persia, Egypt and Spain, through Islamic
cultural exchanges. In the Muslim Spain, the first
examples date back to the 12th-13th c. AD, and
they were followed by a very large and splendid
Hispano-Moresque production during the 14th
and 15th centuries in the area of Valencia and
continued in the following centuries (Figure 1).
From Spain, lustre pottery was introduced in the
Italian peninsula where the famous ‘majolica’
was decorated by this technique since the 15th
and 16th centuries.
Figure 1: Lustre ceramic from Manises, circa XVth century.
Courtesy of Museu de Ceràmica, Barcelona, Spain.
Therefore, lustre pottery has been known for
more than a thousand years but it has always
been perceived as enigmatic. This special
consideration becomes from the secrecy of its
very difficult production technology, kept
zealously during centuries by the potters: “many
make them (the lustre pottery) on the floors of
houses which are locked and under close guard,
for they look on the manner of making the kiln as
an important secret and say that in this consists
the whole art” (Piccolpasso, 1557) 1. Although
an important amount of information is now
available, the theory of this technology is not
completely understood and the practice remains
uncertain because of the number of variables.
The production of lustre was seldom
described in detail before the late 19th century.
However no written records exist for the first four
centuries, therefore there is a risk of interpreting
the ancient technology in terms of current
techniques. This is why an extensive study of
Medieval lustre pottery is carried out in order to
know and to understand the pigments used, the
way of production, the microstructure of the
decoration and its optical behaviour and
2
appearance .
The knowledge of some of the compounds
used as pigments for lustre, the reducing
atmosphere currently used and the resulting
metallic aspect helped to suppose that lustre
was caused by a metallic film created during
firing on the glaze surface, but at present only a
few attempts had been published to verify the
chemical and structural composition of lustre.
These previous studies concluded that silver and
copper were the main components of lustre. But
many questions about metallic and crystalline
character of these components and its complete
microstructure remained still unanswered.
Therefore an especial analytical approach, the
Transmission Electron Microscopy (TEM), was
needed to resolve the composition and
microstructure of lustre. In order to study the
complete in-depth lustre microstructure, a cross
section was preferred for observing the samples
under TEM. The preparation method used for
preparing the thin cross-section specimens was
first developed by Abrahams and Buiocchi for
studying semiconductor epitaxial structures 3.
Two different types of samples were selected
for studying lustre decoration, they were chosen
because they belonged to the extremes of colour
range appeared on lustre pottery. The first
sample (A) is a fragment decorated with redbrown copper-like lustre from Paterna (Spain),
14th century AD, and the second one (B) is part
of a Syrian ceramic, 12th century AD, with a
green-olive yellowish lustre. In both cases,
samples belonged to ceramics decorated with
lustre designs on white tin-glazes.
In TEM, sample A appeared with a
homogeneous surface microstructure formed by
small quasi-spherical clusters, arranged in two
41
different sizes and embedded in an amorphous
matrix (the glaze) (Figure 2). The total thickness
of this structure was between 200 and 500 nm.
A first outer layer was formed by the biggest
clusters, which had a diameter of about 50 nm.
Diameter of the other smaller inner clusters was
between 10 and 20 nm.
Figure 3: TEM image of a green-olive, yellowish lustre. The
inset corresponds to the SAD pattern of silver particles.
Figure 2: TEM image of a red-brown, copper-like lustre. The
inset corresponds to the CBED pattern of a copper particle.
About the composition of these clusters,
TEM-EDS
analyses
indicated
that
the
nanoclusters were particles of pure copper.
Convergent-beam electron diffraction (CBED) in
50 nm diameter particles proved that they were
crystals of metallic copper; inset in Figure 2
shows the face-centred cubic arrangement
pattern, with a cell parameter of 1.80 Å
corresponding to metallic copper.
Sample B showed a slightly different
microstructure in TEM. Also in this case a
nanostructure formed by small clusters
appeared in the surface of the glaze (Figure 3).
Nanoclusters were embedded in the matrix
covering a thickness about 1 µm. Clusters
seemed to be classified in three ranges of size;
the outer layer was constituted by clusters of
diameter between 7 and 10 nm; these first
clusters were continued by a layer of very small
particles of about 4 nm of diameter and the most
inner clusters were the biggest with a diameter
of 15-20 nm.
Summarising,
lustre
is
the
first
nanostructured metallic thin film made by
person, as revealed by Transmission Electron
Microscopy. Considering cultural heritage of this
type of decoration, this is a remarkable point in
the History of the Technology, because
nanocrystal films were produced empirically
since the medieval period and this means a high
level of technological knowledge of materials
science to obtain and to reproduce lustre layers.
Principal publications
J. Pérez-Arantegui, A. Larrea. Trends in Analytical
Chemistry 2003, 22, 327.
J. Pérez-Arantegui, J. Molera, A. Larrea, T. Pradell, M.
Vendrell-Saz, I. Borgia, B. G. Brunetti, F. Cariati, P.
Fermo, M. Mellini, A. Sgamellotti, C. Viti. J. Am.
Ceram. Soc. 2001, 84, 442.
Acknowledgements
This study was supported by P047-2000 research
project of the CONSID-DGA (Aragonese Government),
Spain.
References
1
C. Piccolpasso. I Tre Libri dell’Arte del Vasaio, 1557;
Edizioni all’Insegna del Giglio: Firenze, 1976.
2
J. Molera, M. Mesquida, T. Pradell, J. PérezArantegui, M. Vendrell-Saz. Archaeometry 2001, 43,
455.
3
M. S. Abrahams, C. J. Buiocchi. J. Applied Physics
1974, 45, 3315.
TEM-EDS analyses in the nanoparticles
indicated that they were composed by silver, but
in this case the smaller size of particles did not
allow us to avoid the presence of glaze
components by means only of the microanalytical results. In this second sample, the
electron diffraction was also key in resolving the
nanoparticle nature. SAD patterns (inset of
figure 3) of these particles showing its diffraction
rings proved that nanoparticles were crystals of
metallic silver.
42
CERAMICS FOR HIGH TEMPERATURE STRUCTURAL APPLICATIONS
J. I. Peña, A. Larrea, R. I. Merino, I. de Francisco, P. B. Oliete, V. M. Orera
Excellent chemical stability in oxidizing
atmospheres makes ceramic oxides suitable for
high
temperature
structural
applications.
However, the poor creep resistance and the
presence of low melting point intergranular
phases in conventional ceramics deteriorates
the mechanical behaviour of conventional oxide
ceramics above 1000 ºC. This limitations can be
successfully eliminated in the Al2O3 based
eutectic ceramics grown from melt. This is the
case for the Al2O3-ZrO2(Y2O3) and Al2O3-YAG
systems we have grown using laser assisted
directional solidification. The systems consist of
YSZ or YAG phases, in the form of rods or small
platelets of micron or nanometer size dispersed
into the continuous sapphire phase. Combination
of the outstanding creep behaviour of Al2O3
along its c-axis, together with the huge amount
of clean and strong grain boundaries
characteristic of the eutectic solids results in a
new set of ceramic oxides with excellent creep
behaviour and a good retention of their
mechanical properties up to temperatures above
1-3
1700 ºC even in corrosive environments .
Directionally-solidified eutectic rods or plates
have been produced by the laser-heated floating
zone method using either CO2 or diode stack
4,5
lasers . The mechanical properties tests were
done at the E.T.S. de Ingenieros de Caminos in
Madrid (Prof. J. Llorca group). Flexural strength
was measured using a three-point bend test.
The fracture toughness was determined by the
notch technique and also by the indentation
fracture method using a Vickers indentor.
Several strategies have been used to
improve the mechanical properties of the
composites. On the one side we modified the
characteristic size and shape of the
microstructure by changing the growth
6
parameters . Additionally, we also changed the
yttria content in the Al2O3-ZrO2 composites. The
presence of the different ZrO2 phases, cubic,
tetragonal or monoclinic, was quantified using
Raman and XRD techniques 7. By far the best
mechanical properties were achieved for the
samples with the finest interpenetrating
microstructure in both compounds (Fig. 1 and 2)
and about 1 mol % Y2O3, which corresponds to
the tetragonal ZrO2 phase in the Al2O3-YSZ
composites.
Multiphase
composites
may
develop
thermoelastic residual stresses due to the
differences between the thermal expansion
coefficients of the component phases. Residual
stresses play an important role in the fracture
mechanisms. We have studied these residual
stresses using piezo-spectroscopic and Raman
7,8
techniques . Residual stresses in the Al2O3YAG eutectics are very small (σh = -0.1 GPa)
owing to the light mismatch in thermal expansion
Figure 1: SEM micrograph of Al2O3-ZrO2(Y2O3) eutectic grown
at 10 mm/h. Bright phase is c-ZrO2 and dark phase α-Al2O3.
Scale bar = 20 µm.
Figure 2: SEM micrograph of transverse section of Al2O3-YAG
eutectic grown at 350 mm/h. Bright phase is YAG and dark
phase α-Al2O3.
coefficients. On the contrary large tensile
residual stresses in the sapphire phase develop
in the Al2O3-ZrO2 eutectic when the yttria content
is low and the zirconia is in the monoclinic
phase. These large residual stresses produce
microcracking and a severe deterioration of the
mechanical properties of the composite. On the
contrary, compression residual stresses (σh =
-0.35 GPa) are established in the alumina
phase when the zirconia is either in the
tetragonal or cubic phase. In this case the
eutectic shows an excellent mechanical
behaviour.
43
In Figure 3 we plot the flexural strength
measured in air in rods of about 1 mm diameter
showing a fine microstructure (< 1µm) at RT and
1800 K compared with those measured for the
best SiC and Si3N4 composites. Our materials
are much stronger than any other ceramic
composite reported up to date and their
mechanical properties retention at high
temperatures in air is outstanding.
The Vickers hardness is also high Hv = 16 ±
0.4 GPa in both compounds.[9] The high
strength of the samples is accompanied by a
high toughness. In fact, the fracture toughness
measured by the notch technique in Al2O3-YSZ
is 7.8 MPa.m1/2 at RT 1.
It is interesting to point out here that the
Vickers hardness, fracture toughness and
residual stresses measured in directionally
solidified eutectic plates at ambient temperature
coincide with the values obtained in rods of the
same
composition
and
microstructure.
Consequently
an
excellent
mechanical
behaviour at high temperature is anticipated.
These directionally solidified eutectic surfaces
can be used in wear, impact or thermal resistant
coatings,
thermal
barrier
coatings
or
anticorrosion barriers.
mm diameter or solidified plates up to 500 µm
thick.
Principal publication
R. I. Merino, J. I. Peña, N. R. Harlan, G. F. de la
Fuente, A. Larrea, J. A. Pardo, V. M. Orera, J. Y.
Pastor, P. Poza, J. Llorca. “Ceramic Engineering &
Science Proceedings”. Ed. by Hua-Tay Lin and
Mrityunjay Singh, The American Ceramic Society, OH.
2002, vol. 23, 663.
Acknowledgements
The flexural strength and fracture measurements have
been done by J. Y. Pastor and J. Llorca in the
Universidad Politécnica de Madrid. We acknowledge
finantial support from the Spanish Ministry of Science
and Technology through projects MAT2000-1533-C0302 and MAT2000-1495.
References
1
J. Y. Pastor, P. Poza, J. Llorca, J. I. Peña, R. I.
Merino, V. M. Orera. Mater. Sci. Eng, 2001, A308, 241.
2
A. Sayir, S. C. Farmer. Acta mater. 2000, 48, 4691.
3
N. Bahlawane, T. Watanabe, Y. Waku, A. Mitani, N.
Nakagawa. J. Am. Ceram. Soc. 2000, 83, 3077.
4
J. I. Peña, R. I. Merino, G. F. de la Fuente, V. M.
Orera. Adv. Mater. 1996, 8, 909.
5
A. Larrea, G. F. de la Fuente, R. I. Merino, V. M.
Orera. J. Eur. Ceram. Soc. 2002, 22, 191.
6
J. I. Peña, R. I. Merino, N. R. Harlan, A. Larrea, G. F.
de la Fuente, V. M. Orera. J. Eur. Ceram. Soc. 2002,
22, 2595.
7
N. R. Harlan, R. I. Merino, J. I. Peña, A. Larrea, V. M.
Orera, C. González, P. Poza, J. Llorca. J. Am. Ceram.
Soc. 2002, 85, 2025.
8
V. M. Orera, R. Cemborain, R. I. Merino, J. I. Peña,
A. Larrea. Acta mater. 2002, 50, 4677.
9
A. Larrea, V. M. Orera, R. I. Merino, J. I. Peña. J.
Eur. Ceram. Soc. (in the press).
Figure 3: Flexural strength of several materials measured
by the three points technique in air at different temperatures.
Black squares, Al2O3-YSZ (3 mol%) eutectic with
interpenetrating microstructure. Red circles, Al2O3-YAG grown
at 750 mm/h.
Summarising, using the laser assisted
directional solidification technique and optimized
conditions we have prepared some eutectic
composites
with
exceptional
mechanical
properties. With the experimental equipments
available in our laboratory can be prepare
materials in the form of thin rods of less than 2
44
HYSCORE SPECTROSCOPY OF THE CYTOCHROME b559 OF PHOTOSYSTEM II
REACTION CENTRE
P. J. Alonso, J. I. Martínez
the α and β subunits. Two histidine residues
placed axially respect to the phorphyrin ring with
the hydrophobic domain of each polypeptide act
as ligands of the heme iron.
Cyt b559 was characterized by cw-EPR
spectroscopy a few years ago 5. Its spectra are
typical of a low spin heme iron and can be
described with an fictitious spin S = ½ and an
orthorrombic g-tensor with the following principal
values: gx ≈ 1.5, gy ≈ 2.3, gz ≈ 3.0. Slight
modifications of the gz-value depending on the
preparation and purification have been
described. More recent studies relate these
minor modifications in the cw-EPR spectra with
changes between different redox forms of Cyt
b559 5. More recent studies performed in our
laboratory point out that the conditions of the
detergent used to stabilize the PSII RC sample
is the driving force that induces the observed
changes in the cw-EPR spectra 6.
With those antecedents a HYSCORE study
of Cyt b559 was undertaken. In this case, it is not
possible to work with selectively labeled Cyt b559.
Thus we have also studied heme model
compounds that have similar cw-EPR and
HYSCORE spectra. In these model compounds
two imidazol axial ligands mimic the histidine
residues. By selective isotopic substitution of
iron bond nitrogen atoms in these simpler
systems a direct assignment of the HYSCORE
signals was done. Because of the similarity of
the spectra this assignment can be extended to
the Cyt b559.
The high anisotropy of the cw-EPR spectra
allows making orientation selection HYSCORE
spectra. Different spectra for magnetic field
values corresponding to the principal values of
the g-tensor were measured.
14
N-Hem
12
N-Im
10
8
6
ν1 (MHz)
Cytochromes are electron transfer heme
proteins that are involved in many biochemical
processes and exhibit a large variety of redox
potential. These characteristics allow them to act
as electron carriers in different metabolic
reactions and other processes in living
organisms. The relationship between the
electronic structure of the heme group (the final
acceptor of the first donor in the redox reaction
of cytochromes) and the reaction mechanism is
not well understood in most cases.
As the ferric state of the cytochromes is
paramagnetic, Electron Paramagnetic Resonance (EPR) techniques have been used to
1
characterize this kind of proteins . Continuous
wave (cw-EPR) spectroscopy gives useful
information about the unpaired electronic
1
distribution in the heme centers . Nevertheless,
no information about the hyperfine and
quadrupolar interactions with the neighboring
nuclei can be obtained with this conventional
technique because of its lack of resolution. With
the aim of overcome this limitation ENDOR and,
more scarcely, electron spin echo modulation
(ESEEM) techniques have been applied to study
different heminic systems, both in hemeproteins
and heme model systems 2-3.
It has to be taken into account that in
hemoproteins the Fe3+ paramagnetic entity is
surrounded by many magnetic nuclei (five or six
nitrogen and several protons) interacting with the
unpaired electron. Selective isotopic substitution
would lead to a direct assignment of the signal to
particular nuclei but in the practice this is not
always achievable when working with biological
materials. In this case the use of model systems
can be helpful. Moreover, protein samples are
orientationally disordered systems in most
cases. Thus, the corresponding ENDOR as well
as one-dimensional (1D) ESEEM spectra
strongly overlap and thus are difficult to
disentangle.
On the other hand, the two-dimensional (2D)
ESEEM HYSCORE spectroscopy introduced
some years ago has proved to be useful to study
weak hyperfine interaction with many nuclei in
4
.
orientationally
disordered
systems
Nonetheless, this potential has not yet been
exploited to study heme systems.
We have examine the ferric state of
cytochrome (Cyt) b559 from spinach by means of
the HYSCORE technique. Cyt b559 is an
hemeprotein constituent of the photosystem II
(PSII) reaction center (RC), which is bound to
the D1 and D2 polypeptides of the PSII RC. We
have studied Cyt b559 in D1-D2-Cyt b559 reaction
center complexes, which are the minimum PSII
complexes that are able to perform efficient light
induced primary charge separation. This
hemeprotein consists of two small polypeptides,
4
2
-15
-10
-5
0
5
10
15
ν2 (MHz)
Figura 1: HYSCORE spectrum of a 14N natural abundance
model compound measured at 10 K with an static magnetic
field of 234 mT (gz-spectrum) the separation between the two
fisrt pulse was τ = 96 ns. The dq-dq correlation due to N-Im
and N-Hem are indicated.
As an example, the HYSCORE spectrum
measured with a magnetic field corresponding to
gz (234 mT) in the model compound with a
14
natural content of N is given is figure 1. By
45
comparison with the HYSCORE spectra of 15N
selectively labeled in the porphyrin ring, in the
imidazol moiety or in both, the assignation of the
observed signal to each type of nitrogen atoms
was done
The HYSCORE spectra allow obtaining the
corresponding nuclear splitting of both types of
nitrogen atoms and then, the principal values of
the hyperfine and quadrupolar coupling tensor
and the orientation of their principal axes respect
to the g-tensor.
As all the heme nitrogen atoms are
equivalent in the gz spectra it is followed that the
z-principal axis of the g-tensor is normal to the
heme plane. Consequently, the orientation of the
g-tensor principal axes respect to the molecule
is determine by the angle, Θ, that the X-axis
makes with a Fe-N-Hem bond direction. From
the quadrupolar tensor of the N-Hem atoms is
estimated that 20° < Θ < 38°. This is illustrated
in figure 2.a where the orientation of the g-tensor
X-principal axis in the porphyrine plane is
indicated
a)
b)
y´
IMIDAZOL
PLANE
N
N
N
N
N
Fe
N
N
Fe
N
x´
X
Figura 2: (a) Orientation of the g-tensor X-principal axis in the
porphyrine plane; dashed lines indicate a range for possible
orientation and the continuous arrowed line shows the mean
orientation. (b) The thick line indicates the orientation of the
imidazol plane; the range of possible oreintations is in between
the dashed lines.
From the analysis of the quadrupolar tensor
for N-Im atoms the orientation of the imidazol
plane is obtained. It is depicted in figure 2.b.
Furthermore the g-tensor principal values
strongly suggest that both imidazol plane are
parallel.
An analysis of the g-tensor using the Taylor´s
model 1 indicates that the unpaired electron
density is mainly in a dy´z like-orbital which is
normal to the heme ring and to the imidazol
plane. It is also illustrated in figure 2.b.
As far as the hyperfine interaction with the
nitrogen atoms is concerned the obtained results
indicate that this interaction is mainly isotropic
and the unpaired electronic orbital have a strong
non-bonding character.
The strong similarity between the spectra of
the model compound and Cyt b559 lead to extent
these conclusions to the cytochrome. In
particular the structure of the heminic center in
this protein should be the same as the one
depicted in figure 2. It is worth of noting that in
spite of the observed principal g-values
modification no differences are found in the
interaction
parameters
when
detergent
conditions used to stabilize Cyt b559 samples
change.
As it has been commented above, the
hyperfine data indicate that the unpaired
electron is localized in confined iron orbital with
a negligible mixture of p-orbitals. This makes
very unlikely that any substrate or reactive can
be located close enough to the orbital occupied
by the exchangeable electron for a direct onestep
electron
exchange.
The
transfer
mechanism could be better understood if it were
a multistage complex process where the metal in
the heme group acts as a final electron
reservoir. So, the g-tensor principal values would
mainly depend on the metal electronic structure
and near environment whereas measured redox
potential would rather be related with the
accessibility of mediators and the actual reaction
process in the experiment. Such processes will
depend in a complex way on the whole protein
conformation. That would explain that there is
not a direct relationship between the cw-EPR
signal and redox potential as it was assumed
5
before .
Finally we want to point out that this
assertion could be considered as a more general
conclusion
being
extended
to
other
cytochromes. Anyway, this work proves the
strong
potentiality
of
the
HYSCORE
spectroscopy to obtain relevant information
about
the
structure
and
function
of
metalloproteins.
Principal publication
I. García-Rubio, J. I. Martínez, R. Picorel, I. Yruela,
P.J. Alonso. J. Am. Chem. Soc. 2003, 125, 15846.
Acknowledgements
This work was supported by the CONSI+D (DGA, local
government of Aragón) under contract P111/2001.
References
1
C. P. S. Taylor. Biochem. Biophys. Acta 1977, 491,
137.
2
N. D. Chasteen, P. A. Snetsinger. In Physical
Methods in Bioinorganic Chemistry. Spectroscopy and
Magnetism. L. Que Editor University Science Books.
Sausalito (CA, USA) 2000. ch 4.
3
F. A. Walker. Inorg. Chem. 2003, 42, 4526.
4
J. J. Shane, P. Höfer, E. J. Reijerse, E. de Boer. J.
Magn. Reson. 1992, 99, 596.
5
D. M. Stewart, G. w. Brudvig. Biochem. Biophys.
Acta 1998, 1367, 63.
6
I. Yruela, I. García-Rubio, M. Roncel, J. I. Martínez,
V. M. Ramiro, J. M. Ortega, P. J. Alonso, R. Picorel.
Photochem. Photobiol. Sci. 2003, 2, 437.
46
ENHANCED ANISOTROPY OF NANOSIZED CoCLUSTERS: EFFECTS FROM SURFACE
AND INTER-PARTICLE INTERACTIONS
F. Luis, J. M. Torres, L. M. García, J. Stankiewicz, J. Bartolomé, F. Petroff
Clusters of magnetic materials, like Fe, Co,
and Ni, have technological interest for
application in future high-density information
storage devices. In addition, they enable us to
investigate how the magnetic properties evolve
as the material’s size changes from the
macroscopic towards the atomic limits.
Figure 1. Transmission electron microscopy (TEM) of a cross
section of a multilayer showing the quasi-ordered
arrangement of Co nanospheres (black dots).
The magnetic anisotropy of nanometer-sized
metallic clusters determines the stability of their
magnetic moments against thermal fluctuations.
Therefore, this magnitude plays a crucial role for
applications, since, in fact, it limits the minimum
size that a particle must have to store
information. The continuous interest in
increasing the density of recording media has
motivated a very intense research activity
devoted towards understanding the physical
origin of the magnetic anisotropy and finding
new methods to enhance it 1. In our work, we
have experimentally studied how the activation
energy U that is required to flip the magnetic
moment of a Co nanosphere depends on its size
and on the interaction with neighboring clusters
in dense arrays.
Clusters containing between 25 and 4000 Co
atoms are formed by aggregation of Co atoms
deposited by rf sputtering on a flat alumina
(Al2O3) surface. The average size of the clusters
can be controlled by increasing the net amount
of Co deposited per layer. The clusters are
nearly spherical and show the atomic packing
characteristic of the fcc crystallographic phase.
They are protected against subsequent oxidation
by a layer of alumina. Multilayers prepared by
piling up a number of these Co/Al2O3 bilayers
show a quasi-ordered spatial arrangangement
that, for nearest neighbors, resembles that of a
hexagonal close-packed structure (see Fig. 1) 2.
The effective activation energy U for clusters
of average diameter ⟨D⟩ has been estimated
from a scaling analysis 3 of the out-of-phase
component of the ac magnetic susceptibility.
From this value, we estimate the effective
3
anisotropy Keff = U/V, where V = (π/6)⟨D⟩ is the
average particle’s volume. Our results, shown in
Fig. 2, show that Keff of Co nanospheres is
larger than the anisotropy constant of bulk fcc
Co and that it strongly depends on the cluster’s
size.
Bulk fcc
Figure 2. Size dependence of the effective anisotropy of Co
nanospheres. The solid (red) line is a least squares fit to
equation Keff = Kbulk + Ks/D, where Kbulk is the anisotropy of bulk
fcc Co (horizontal line) and Ks = 0.33 mJ/m2 is the surface
anisotropy constant.
The observed enhancement is approximately
proportional to the fraction of atoms located at
the surface of the clusters. We associate this
effect with the low symmetry of the surface
atomic sites that might lead to a reduced
quenching of the orbital magnetic moments, thus
also increasing the spin-orbit interaction energy
that is at the origin of the magnetic anisotropy 4.
The strong pinning of the surface spins therefore
dominates the magnetization switching time for
the whole cluster.
For applications, it is also crucial to know how
magnetic dipolar interactions modify the
superparamagnetic
relaxation
rate.
The
importance of this effect is evident in high
density
recording
media.
Unfortunately,
experiments performed until now give different
5,6
and even contradictory results . It is usually
very complicated to disentangle the influence of
the dipole-dipole interactions from other effects,
such as size-dependent anisotropy, cluster
47
aggregation, direct exchange interactions, etc.
Theoretical models are also not free from
contradictions, predicting that the reversal of
magnetic moments becomes either faster or
slower as the dipolar interactions are switched
on. In order to solve this long debated and
complicated puzzle, experiments performed on
simple systems are therefore highly desirable.
By varying the number N of layers while
keeping the average cluster’s size constant, we
have been able to study how the dipolar
interactions between the clusters modify the
average activation energy. As Figure 3 shows,
the blocking temperature TB increases very
rapidly for N ≤ 5 and then it saturates to a nearly
constant value. By contrast, experiments
performed on a multilayer with N = 20 but larger
separation between layers show exactly the
same TB value as that of a single layer.
U = KsS + A Nnn
where Ks is a surface anisotropy constant, S =
2
π D is the surface area of the nanosphere and A
is a parameter that depends on the spatial
arrangement of clusters in the array. The crucial
role played by the atoms located at the cluster’s
surface might be employed to modify, read
enhance, the magnetic anisotropy by simply
changing the properties of the interface with the
embedding matrix. In addition, our study shows
that interparticle intreractions estabilizes the
particle’s magnetization in zero magnetic field.
By contrast, the switching speed of the magnetic
moment by an external field, as when a bit is
stored, is nearly unaffected by interactions.
Principal publications
F. Luis, J. M. Torres, L. M. García, J. Bartolomé, J.
Stankiewicz, F. Petroff, F. Fettar, J. L. Maurice, A.
Vaurès. Phys. Rev. B 2002, 65, 094409
F. Luis, F. Petroff, L. M. García, J. Bartolomé, J.
Carrey, A. Vaurès. Phys. Rev. Lett. 2002, 88, 217205;
ibid 2003, 90, 059706
Acknowledgements
This research has been partly funded by Spanish
(grant MAT 99/1142) and the European ESPRIT
(contract MASSDOTS).
Figure 3. a) Variation of the blocking temperature with the
number of layers; dots, separation between adjacent layers 3
nm; triangles, separation between layers 10 nm. b) Dots, same
data as in a) plotted as a function of the average number of
nearest neighbor clusters located in adjcent layers; crosses,
average activation energy estimated as the slope of the
Arrhenius law frequency-dependence of the ac susceptibility
blocking temperatures.
These results neatly show that the
magnetization switching becomes slower with
increasing the interactions’ strength. In addition,
the rapid saturation as a function of N suggests
that the main contribution comes from the
interaction with the first shell of neighbors.
Indeed, if we plot the same data as a function of
the average number N⊥ of neighbors that a
cluster has in the two nearest layers, we find that
both TB and U are simply proportional to it (Fig 3,
panel b).
References
1
R. L. White. J. Mag. Mag. Mater. 2000, 209, 1; D.
Weller, A. Moser. IEEE Trans. Mag. 1999, 35, 4423.
2
D. Babonneau, F. Petroff, J. L. Maurice, F. Fettar, A.
Vaurès. Appl. Phys. Lett. 2000, 76, 2892.
3
M. I. Shliomis, V. I. Stepanov. Adv. Chem.
Phys.1994, 87, 1; F. Luis, J. Bartolomé, J. Tejada, E.
Martínez. J. Mag. Mag. Mater. 1996, 157-158, 266.
4
P. Bruno. Phys. Rev. B 1989, 39, R865.
5
J. L. Dormann, L. Bessais, D. Fiorani. J. Phys. C
1988, 21, 2015; W. Luo, S. R. Nagel, T. F.
Rosenbaum, R. E. Rosensweig. Phys. Rev. Lett. 1991,
67, 2721; J. L. Dormann, F. D'Orazio, F. Lucari, E.
Tronc, P. Prenté, J. Jolivet, D. Fiorani, R. Cherkaoui,
M. Noguès. Phys. Rev. B 1996, 53, 14291.
6
S. Mörup, E. Tronc. Phys. Rev. Lett. 1994, 72, 3278;
S. Mörup, F. Bödker, P. V. Hendriksen, S. Linderoth.
Phys. Rev. B 1995, 52, 287.
For the first time, profitting from the very high
quality of the samples, we have been able to
directly compare the experimental results to
theoretical predictions with almost no free
parameters. The calculated results (solid lines in
Fig. 3) account very well for the observed
increase of TB and for the dominant role of
nearest neighbors.
Our results can be summarized in a very
simple expression, which relates the activation
energy of small clusters to their size and to the
number Nnn of nearest neighbor spins, as follows
48
A THIAZYL-BASED ORGANIC FERROMAGNET: MAGNETISM AND SPIN-DENSITY
DISTRIBUTION BY POLARISED NEUTRON. DRIFFRACTION EXPERIMENTS AND AB
INITIO CALCULATIONS
J. Campo, F. Palacio, J. Luzón, G. J. McIntyre, A. Alberola, J. M. Rawson, C. Paulsen, R. D.
Farley
Here we report on the magnetism of the pO2N·C6F4CNSSN• radical and on the study of its
spin-density distribution using polarized-neutron
diffraction and ab initio calculations techniques.
Low
temperature
ac
susceptibility
measurements on a single crystal of pO2N·C6F4CNSSN• were made between 0.6 and
2.5K on a SQUID magnetometer in a field of 2G.
The crystal, when oriented both perpendicular
and parallel to the [001] axis, showed an abrupt
increase in the out-of-phase susceptibility below
1.4 K, reaching a maximum at 1.3K, consistent
with the onset of bulk ferromagnetic order at Tc
= 1.32±0.02K [Fig. 2]. Little anisotropy in M vs H
or χ vs T data was observed. The difference in
the data is attributed to demagnetising effects
arising from the sample geometry.
35
30
25
χ' (emu/mol)
In 1928 Heisenberg proposed 1 that bulk
ferromagnetic order would only ever be achieved
in systems containing heavy atoms, i.e. metals,
their oxides and related derivatives. Indeed it
was not until 1991 that the first organic
ferromagnet was reported; the β-polymorph of
the radical p-NPNN was shown to order below
0.6K 2. Since then a number of other organic
radicals have been found to undergo bulk
ferromagnetic order, although they almost
invariably order below 1K. The nitroxide-based
diradical DOTMDAA is the sole exception,
3
ordering at 1.6K . We have previously shown
that the thiazyl radical p-NCC6F4CNSSN• orders
as a canted antiferromagnet at 36K under
ambient pressure 4, the highest reported
magnetic ordering temperature for an organic
radical. By replacing the CN group by Br a
paramagnetic system possessing very weak
antiferromagnetic interactions is obtained 5. We
have recently reported that if the CN group is
substituted by NO2 to give the pradical,
ferromagnetic
O2N·C6F4CNSSN•
6
ordering is observed below Tc = 1.3 K . This is
the first S-based organic radical, entirely metalfree, to undergo ferromagnetic ordering and only
the second organic radical to order as a
ferromagnet above 1K.
These different magnetic behaviors are due
to the change in the molecular packing (see Fig.
1 for the p-O2N·C6F4CNSSN•, and consequently
a substantial modification of the magnetic
interaction pathways. Knowledge of the spindensity distribution in the dithiadiazolyl radical
ring allows us a better understanding of the rich
magnetism of DTDA derivatives and hence
helps in the design of new organic ferromagnets
based on the DTDA ring with higher TC.
20
15
[001] axis
(001) axis
10
5
0
0
1
2
3
4
5
6
T (K)
Figure 2. Single-crystal ac susceptibility of the pO2N·C6F4CNSSN• radical in an applied field of 2 G and at 1.11
Hz.
Figure 1. Crystal structure of p-NO2.C6F4CNSSN•
The polarized-neutron diffraction experiment
was performed on the D3 lifting-counter
diffractometer at the ILL at 1.5 K in an applied
field of 9 T. A multipolar model of the spin
density (Fig.3) was fitted to the measured
flipping ratios. Almost all the spin density is
localized in the nitrogen and sulfur p orbitals
perpendicular to the DTDA ring (0.281µB and
0.247µB, respectively). These orbitals generate
the Single Occupied Molecular Orbital (SOMO).
Some negative density is observed between the
sulfur and nitrogen atoms that can be due to
covalence and polarization effects. In addition, a
49
small negative density is observed (-0.055µB) on
the carbon site of the DTDA ring due to
polarization effects. The spin density over the
rest of the radical is below the limits of the
experimental accuracy 7.
Figure 4. Spin density distribution of the p-O2N·C6F4CNSSN•
radical calculated with the Dmol3 package (BLYP functional,
molecular calculation). The red surface is the contour of
0.0002 µB/Å3 and the blue one is the contour of –0.0002 µB/Å3.
Principal publication
A. Alberola, R. J. Less, C. M. Pask, J. M. Rawson, F.
Palacio, P. Oliete, C. Paulsen, A. Yamaguchi, R. D.
Farley. Angew. Chem. Int. Ed. 2003, 42, 4782.
J. Luzón, J. Campo, F. Palacio, G. J. McIntyre, A. E.
Goeta, C. M. Pask, J. M. Rawson. Polyhedron 2003,
22, 2301.
Figure
3.
Spin-density
reconstruction
of
the
pO2N·C6F4CNSSN• radical projected along the perpendicular to
the CNSSN mean plane.
To support the experimental modeling, ab
initio calculations were performed at the
generalized gradient approximation level, using
several exchange-correlation functionals (PW91,
BLYP,VWM) with a double numerical basis set
including functions and numerical integrations,
as implemented in the Dmol3 software based on
density functional theory. Both periodic (crystal)
and molecular calculations were made.
The ab initio calculations (Fig 4 and Table I)
confirm the experimental results and, in
particular, they show that the negative spin
density in the plane of the DTDA ring is not a
spurious effect of the multipolar model used.
Such a negative spin density plays an important
role in the ferromagnetic behavior of the
O2N·C6F4CNSSN• radical. The spin populations
in the rest of the molecule were also obtained. In
the carbon atoms negative and positive low spin
density populations alternate due to polarization
effects. Only a weak indication of the latter was
observed experimentally, which emphasizes the
importance of combining experiment and ab
initio calculations in this kind of studies.
Acknowledgements
We would like to thank the E.P.S.R.C., the C.I.C.Y.T.
(grant MAT2001-3507-C02-02) for financial support,
and the European Science Foundation programme
“Molecular Magnets” for partial support to the
collaborative activities. One of us, JL, thanks the ILL
for a PhD research fellowship.
References
1
W. Heisenberg. Z. Phys. 1928, 49, 619.
2
H. Tamura. Chem. Phys. Lett. 1991, 186, 401.
3
R. Chiarelli, M. A. Novak, A. Rassat, J. L. Tholance.
Nature 1993, 363, 147.
4
F. Palacio, G. Antorrena, M. Castro, R. Burriel, J. M.
Rawson, J. N. B. Smith, N. Bricklebank, J. Novoa, C.
Ritter. Phys. Rev. Lett. 1997, 79, 2336.
5
G. Antorrena, J. E. Davies, M. Hartley, F. Palacio, J.
M. Rawson, J. N. B. Smith, A. Steiner. J. Chem. Soc.,
Chem. Commun. 1999, 1393.
6
A. Alberola, R. J. Less, C. M. Pask, J. M. Rawson, F.
Palacio, P. Oliete, C. Paulsen, A. Yamaguchi, R. D.
Farley. Angew. Chem. Int. Ed. 2003, 42, 4782.
7
J. Luzón, J. Campo, F. Palacio, G. J. McIntyre, A. E.
Goeta, C. M. Pask, J. M. Rawson. Polyhedron 2003,
22, 2301.
Table I. Ab initio and experimental spin-density
populations in the p-O2N·C6F4CNSSN• radical
µB
BLYP
molec.
N2
0.226
PW91
molec.
0.220
VWM
molec.
BLYP
crystal
This
experim.
0.225
0.214
0.247
S1
0.308
0.312
0.310
0.317
0.281
C5
0.065
-0.061
-0.062
-0.061
-0.055
C1
-0.003
-0.003
-0.003
-0.003
C2
0.001
0.001
0.001
0.002
C3
-0.004
-0.004
-0.004
-0.004
C4
0.005
0.002
0.002
0.004
F2
0.000
0.000
0.000
0.001
50
TOWARDS THE MAGNETIC REFRIGERATION: THE MAGNETOCALORIC EFFECT.
A NEW METHOD OF CHARACTERIZATION WITH AN ADIABATIC SYSTEM
R. Burriel, E. Palacios, L. Tocado
The Kyoto protocol establishes a gradual
reduction of gas emissions to control the
greenhouse effect and the destruction of the
ozone layer. The conventional refrigeration
systems are based on the cyclic compression
and expansion of some fluid with the subsequent
gas-liquid transitions. The heat transferred from
the cool source to the hot one is basically the
latent heat of vaporization. The typical fluids
used for this purpose are highly contaminant in
the sense of the Kyoto protocol. They are
confined to closed circuits, but sooner or later
they leak to the atmosphere. Therefore some
alternatives are being searched. One of the most
promising
methods
is
based
on
the
magnetocaloric effect (MCE). The exchange
fluid does not need to have a phase transition
and can be an innocuous liquid like just water or
a solution of water - alcohol.
The MCE is the heating or cooling of a
sample when a magnetic field H is applied or
removed. The reduction of magnetic entropy
provoked by the field implies an increase of
lattice vibrations in an adiabatic process and,
consequently, a raise of temperature. It is tied to
the alignment of the magnetic moments,
decreasing the number of thermally accessible
Zeeman states, which is 2J+1 for H = 0, being J
the quantum angular momentum for the
magnetic atom. The inverse process, known as
adiabatic demagnetization, consists on removing
the magnetic field acting on a paramagnetic salt,
which has been precooled in an external field
down to liquid helium temperatures or lower.
At higher temperatures, the alignment of the
spins needs more and more intense fields to
compensate for the thermal excitations. This
problem can be solved by choosing a
ferromagnetic substance near the Curie point TC,
where the susceptibility increases sharply.
Figure 1 shows the typical temperature
dependence of the entropy for a ferromagnetic
material near TC at zero field and in an applied
field H. One of the most efficient processes
working continuously is the Ericsson cycle,
ABCDA, formed by two isothermal and two
isofield lines. The most relevant quantities
describing the main features of the material as a
refrigerant are the isothermal entropy change
∆ST and the adiabatic temperature increment ∆TS
when a field H is applied. A suitable substance
for magnetic refrigeration should have the
highest possible values of these magnitudes in
the range of the working temperatures.
The characterization of a given material can
be done with magnetization and field dependent
heat capacity measurements (Cp,H). The entropy
can be obtained from the integrals
H
⎛ ∂M (T , H ) ⎞
∆S T = ∫ ⎜
⎟ dH or
∂T
⎠ p,H
0⎝
S (T , H ) =
T
∫
0
C p , H (T )
T
dT
then,
∆ST = S(T,0) - S(T,H) and ∆TS = [T ( S ) H − T ( S ) 0 ]S
being T(S)H the inverse function of S(T,H) for a
constant H.
The easiest experimental measurement is
the magnetization, but this method allows having
only ∆ST and not ∆TS, for which one would need
the heat capacity at every field
H
T ⎛ ∂M (T , H ) ⎞
∆TS = −
⎜
⎟ dH
C
∂T
⎠ p, H
p,H ⎝
0
∫
Moreover, the first integral is based on the
⎛ ∂M ⎞
⎛ ∂S ⎞
Maxwell relation ⎜
⎟ =⎜
⎟ that is not
∂
T
⎝
⎠ H ⎝ ∂H ⎠T
valid in a first-order transition. These constrains
make doubtful the results based on
magnetization data. Therefore, the heat capacity
is the main experimental characterization
technique of MCE materials. In any case, near
first-order transitions even the heat capacity is
not as precise as in other conditions, because
the relaxation time becomes very large. Another
drawback of the Cp method is that it requires
measurements virtually from 0 K for each field in
order to avoid cumulative errors in the entropy
integrals which arise when Cp,H is different from
Cp,0 at low temperatures, far from the interesting
range.
An alternative possibility is a direct
measurement of ∆TS. In combination with heat
capacity at zero field it allows to determine the
isofield curves in an S/T diagram because T(S)H =
T(S)H=0 + ∆TS, and T(S)H=0 is obtained from Cp,0
data. The usual experimental procedure is to
apply a pulsed field or to plunge the sample into
a strong static field. The procedure takes few
51
107
5T
4T
106
T(K)
3T
∆ TS
2T
105
1T
104
H=0
0
500
1000
time(s)
Figure 2. Adiabatic temperature change in Tb5Si2Ge2
constant field, the thermal drift due to small
errors of adiabaticity is typically lower than 0.2
K/hour. It can be corrected observing the slope
of T(t) at constant field so that the accuracy in
∆TS is about 0.02 K, better than 1% in the
interesting MCE ranges.
Materials suitable for magnetic cooling
should have a large angular and magnetic
moment and Tc near the working temperature,
most frequently room temperature. They must
also be good thermal conductors in order to give
a fast heat exchange.
The first prototypes of magnetic refrigeration
machines used pure Gd metal, which has Tc =
294 K and applied fields of 7 T. The application
of the MCE for refrigeration has been considered
as a competitive and alternative method since
the discovery of the so called giant
magnetocaloric effect (GMCE) in Gd5Si2-xGe2+x
3
. For compositions near x = 0 this alloy
undergoes a first-order transition from a
paramagnetic
monoclinic
phase
to
a
ferromagnetic orthorhombic one at 276 K. The
transition can be induced at slightly higher
temperatures by the application of an external
field. The entropy change is due to the alignment
of the magnetic moments and a large volume
contraction in the ferromagnetic phase. As a
result, the entropy change is about twice larger
than in pure Gd metal. Moreover, the transition
temperature can be tailored between 130 K and
280 K by choosing the composition x, what
allows adjusting the working temperature and a
good regeneration process, expanding the
difference between the hot and cold sources.
The use GMCE compounds allows working
with moderate fields, attainable by conventional
electromagnets, and making the procedure
competitive with respect to the gas compressionexpansion cycles. Additionally, the GMCE based
refrigeration is about 20 % more efficient than
the conventional procedure, which implies some
energy saving. Moreover, the mechanical design
is simpler, using a low pressure innocuous fluid
as a heat exchanger.
Since the report on Gd5Si2-xGe2+x many
other compounds are being studied that could
be suitable for working in other temperature
ranges. In the family R5Si4 where R is a rare
earth atom, the gradual substitution of Tb for Gd
decreases the transition temperature, whereas
the substitution of Si by Ge increases ∆ST.
The RNi2 and RAl2 compounds have proved
to be good magnetic refrigerants in the low
temperature range, 10 K to 100 K.
Mn3GaC has the perovskite structure with a
first-order transition at T0 = 160 K from an
antiferromagnetic phase in the low temperature
region to a ferromagnetic one. The transition can
be induced below T0 by an external field. Direct
measurements of the MCE (Figure 3) have
shown high negative ∆TS, independent of the
4
field intensity above a threshold value . The
threshold field increases with decreasing
temperature below T0 but the MCE is constant in
a wide temperature range.
Other interesting families are MnAs,
MnFeP1-xAsx, Fe0.49Rh0.51 and the Heusler alloys
Ni2+xMn1-yGa1-x+y (x,y <<1) which have magnetic
form memory effects.
0 to 1T
1T to 0
0 to 3T
3T to 0
0 to 5T
5T to 0
1
∆TS (K)
seconds so that the heat gain or loss of the
sample can be neglected. This method has the
experimental problem of lack of adiabaticity and
the dissipated heat by induced currents for a
conducting sample in a fast variable field.
1
Dan’kov et al. have estimated the accuracy to
be not better than 8 % in ∆TS with this method.
We have developed a new method 2 based
on a modified adiabatic calorimeter primarily
designed to measure heat capacity by the heat
pulse method. For the measurement of ∆TS the
sample is maintained in adiabatic conditions
while a field is applied quasi-statically. The
process takes several minutes. Figure 2 shows
the thermal evolution of Tb5Si2Ge2 when the field
is increased from 0 to 5 T in steps of 1 T. In a
0
-1
130
140
150
160
170
T(K)
Figure 3. Adiabatic temperature increment in Mn3GaC,
for several positive and negative field increments.
Acknowledgements
Financial support from the Spanish Ministerio de
Ciencia y Tecnología, Project MAT2001-3507-C02-02.
References
1
S. Yu Dan’kov, A. M. Tishin, V. K. Pecharsky, K. A.
Geschneidner Jr. Rev. Sci. Instr. 1997, 68, 2432.
2
th
L. Tocado, E. Palacios, R. Burriel. 6 Mediterranean
Conference on Calorimetry and Thermal Analysis
MEDICTA 2003, Oporto (Portugal), August 2003, 135.
3
V. K. Pecharsky, K. A. Geschneidner Jr. Phys. Rev.
Lett. 1997, 78, 4494.
4
R. Burriel, L. Tocado, E. Palacios, H. Wada. Joint
European Magnetic Symposia JEMS’04, Dresden
(Germany), 2004.
52
SYNCHROTRON X-RAY RESONANT SCATTERING IN METALLIC OXIDES: CHARGE AND
ORBITAL ORDERING
J. García, G. Subías, J. Blasco, M. G. Proietti, M. C. Sánchez, J. Herrero-Martin
Mixed-valence transition-metal (TM) oxides
exhibit many interesting properties such as
superconductivity, colossal magnetoresistance
and metal-insulator phase transitions. Generally,
the description of the electronic state of these
compounds is made on the basis of the ionic
model proposed by Goodenough and it implies
the spatial or temporal charge localization on the
transition-metal
atoms.
Following
this
framework, the low temperature insulating
phases of these oxides have generally been
described as a periodic ordering of distinct ionic
states in the lattice. This phenomenology, socalled charge ordering (CO), has become
nowadays a main topic in the description of TM
oxides, such as manganese perovskites.
Intimately related to the charge ordering, it has
also been proposed the concept of orbital
ordering (OO), as the orientational ordering of
the d-orbitals of the transition-metal atoms in the
lattice. The two archetype examples of charge
and orbital ordering are Fe3O4 (magnetite) and
(the
mother
compound
of
LaMnO3
magnetoresistive manganites), respectively.
The characterization of the charge-orbitalordering (COO) phenomena is a hard and
controversial task up to now. Generally, the
observation of different crystallographic sites by
either x-ray or neutron diffraction techniques has
been considered as a proof of charge ordering.
A direct way to demonstrate the onset of a longrange periodic charge arrangement is the
observation of superlattice reflections by the
recently developed X-ray Resonant Scattering
technique in modern synchrotron radiation
facilities. The appearance of a resonance at the
transition-metal K absorption edge is due to the
out-of-phase interference of identical (or almost)
crystallographic sites because of the difference
in the atomic anomalous scattering factors f. The
anomalous part of the scattering factor, f'(E) +
if"(E), is related to the x-ray absorption
coefficient µ. For dipolar transition, resonant
reflections can then originate by either the
different energies of s-p excitations for atoms
with different valence states (CO reflections) or
by the directional splitting of the p-unoccupied
states in an anisotropic local environment
(Anisotropic Tensor of Susceptibility, ATS,
reflections, often associated to OO reflections).
In the course of our research, we have
investigated the COO phenomena carrying out
X-ray Resonant Scattering experiments in two
relevant systems. The first one includes Fe3O4
and related spinel ferrites. The second one is
Nd0.5Sr0.5MnO3 as example for half-doped
manganites. Both systems showed a metalinsulator phase transition with decreasing the
temperature, the low temperature phase being
described as a COO phase. We have shown
that the observed resonant reflections in the two
systems can be easily explained only
considering the anisotropy of the local
geometrical structure around the excited TM
atom.
Magnetite was the first material where a CO
transition was proposed to explain the insulator
behaviour below TV ∼ 120 K (Verwey transition).
It crystallizes in the spinel cubic structure (space
group Fd-3m) at room temperature. The formula
3+
2+
3+
unit can be written as Fe [Fe ,Fe ]O4 where
the bracket indicates atoms located at the
octahedral sites while cations outside the
bracket are at the tetragonal sites. According to
this formula, 2+ and 3+ Fe ions are dynamically
disordered at the same crystallographic site.
This dynamical transformation of Fe2+ into Fe3+
implies the motion of the electron to be
responsible for the metallic conductivity. Then,
the insulator behaviour was explained in terms
of localization of the mobile electron at the
octahedral sites, giving rise to a long range
spatial CO pattern (Verwey model). Spinel
ferrites are obtained from Fe3O4 by partial
substitution of the Fe ions by other divalent
cations. In particular, Co2+ locates at the
2+
octahedral site
in CoFe2O4 whereas Mn
occupies the tetrahedral site in MnFe2O4.
X-ray resonant scattering experiments were
carried out on Fe3O4 1,2, MnFe2O4 and CoFe2O4
single crystals, grown by floating zone method in
our laboratory, at the beam-line D2AM at the
ESRF (Grenoble, France). Symmetry forbidden
(002) and (006) reflections were measured at
room temperature, below TV and in the case of
magnetite, above the Néel temperature (TN) in
order to check any effect associated to the onset
of the ferrimagnetism. The azimuthal angle
(rotation around the scattering vector Q=k'-k)
dependence and polarization analysis (σ-σ’ and
σ-π’ components for σ–polarised incident bem)
of the scattered intensity were also analysed.
Figure 1 compares the energy dependence of
the diffracted intensity of (002) and (006)
reflections at the Fe K-edge at room temperature
for the three spinel ferrites. The spectra shows
three main features whose origin we have
determined
experimentally:
a
pre-edge
resonance (dipole-quadrupole transitions at the
tetrahedral Fe ion), a main resonance at the
absorption K-edge and an energy extended
modulation (dipole transitions at the pseudooctahedral metal ion). The dipolar part of the
spectra has been analysed using a tensorial
formalism for the anomalous scattering factor. In
the local frame of the pseudo-octahedron,
trigonal-distorted, the scattering tensor is
diagonal with two main components, parallel and
perpendicular to the trigonal axis. This analysis
reproduces well the energy, azimuthal and
polarization dependences. Moreover, the
energy-dependent spectra at temperatures
53
below TV or above TN in magnetite are identical
to the room temperature one.
and (2) nearly-regular [the three components in
the diagonal are identical, f2]. Figure 2 compares
the x-ray scattering data to the best-fit semiempirical model, obtained for δanis = f1par1
1 2
f perp = 1.6 eV and δchem = f - f = 0.7 eV, for
both the supposed “CO” and “OO” reflections.
Although the experiment probe the existence of
two kinds of Mn atoms, we demonstrate that
they cannot be identified as (1) Mn3+ and (2)
4+
1
2
Mn ions with a δchem = f - f = 4.5 eV
determined from XANES spectroscopy. Then,
the “CO” reflections are naturally explained by
the different local geometry of the two Mn sites
and the “OO” reflections as due to the anisotropy
of the tetragonal local distortion at one of the Mn
sites without including any ordering of the Mn dorbitals, i.e. Jahn-Teller effect.
Figure 1. Energy dependence spectra of (002) [closed
symbols] and (006) [open symbols] reflections. Solid lines are
the respective fluorescence spectra. Lines are a guide for the
eye and asterisks mark spurious Renninger reflections.
All these results show: First, the atomic
scattering factor is identical among the different
octahedral atoms in magnetite pointing out to the
lack of charge localization (temporal or spatial)
in the sense of bimodal CO of ionic states.
Secondly, the anisotropy of the anomalous
scattering factor is mainly originated by the
anisotropy of the local geometrical symmetry of
the octahedral atom instead of a supposed 3d
orbital ordering.
In the case of half-doped manganites, several
x-ray resonant scattering studies have claimed
on the observation of real COO phases.
However, neither our previous XANES (X-ray
Absorption Near Edge Structure) measurements
on these manganites nor a proper reexamination of the x-ray resonant scattering
3,4
supported this
data reported in the literature
electronic localization at atomic scale.
We have recently performed a X-ray resonant
scattering experiment at the beam line ID20 at
the ESRF (Grenoble, France) at the Mn K-edge
5
in a Nd0.5Sr0.5MnO3 single-crystal , also grown
by floating zone method in our laboratory. The
low temperature phase of this compound has
also been described as a COO phase within a
checkerboard pattern of Mn3+ (Jahn-Teller ion)
and Mn4+ ions according to the antiferromagnetic
CE-type phase below TN ~170 K. We observe
dipole resonance at the Mn K-edge for the low
temperature superlattice (300) and (030)
[assigned to CO] and forbidden (05/20)
[assigned to OO] reflections. The energy,
azimuthal angle and polarization dependences
of these reflections have nicely been analysed
using a semi-empirical structural model for the
tensorial atomic scattering factors: Two nonequivalent crystallographic octahedral sites are
found for the Mn atoms below TN, (1) tetragonaldistorted [described with two components in the
diagonal, f1par and f1perp to the tetragonal axis]
Figure 2. Energy dependence spectra of (030) and (05/20)
reflections at the Mn K-edge at T=60 K (symbols) compared to
the best-fit structural model (lines) at maximum and minimum
azimuthal ϕ angles.
Summarizing, we conclude that no charge
localization occurs on the transition-metal atoms
in either magnetite or the half-doped NdSrmanganite. This result might force the scientific
community to change the atomic concept of
electronic localization in mixed-valence TM
6
oxides .
Acknowledgements
This work was partially supported by the CICyT MAT02-0121 project and DGA.
References and Principal publications
1
J. García, G. Subias, M. G. Proietti, H. Renevier, Y.
Joly, J. L. Hodeau, M. C. Sánchez, J. F. Bérar. Phys.
Rev. Lett. 2000, 85, 578.
2
J. García, G. Subias, M. G. Proietti, J. Blasco, H.
Renevier, J. L. Hodeau, Y. Joly. Phys. Rev. B 2001,
63, 054110.
3
J. García, M. C. Sánchez, J. Blasco, G. Subías, M.
G. Proietti. J. Phys. Condens. Matter 2001, 13, 3243;
J. García, M. C. Sánchez, G. Subías, J. Blasco. J.
Phys. Condens. Matter 2001,13, 3229.
4
J. García, G. Subías, Phys. Rev. B 2003, 68, 12701.
5
J. Herrero-Martin, J. García, G. Subías, J. Blasco, M.
C. Sánchez. Phys. Rev. B 2004, 70, Art nº 024408.
6
J. García, G. Subías. J. Phys. Condens. Matter 2004,
16, R145.
54
NEW OPPORTUNITIES IN TRACE ELEMENTS STRUCTURAL CHARACTERIZATION:
HIGH-ENERGY X-RAY ABSORPTION NEAR-EDGE STRUCTURE SPECTROSCOPY.
J. Chaboy
Modern synchrotron radiation facilities provide
indispensable tools for research in a large
number of different fields of science like Physics,
Chemistry, Biology, as well as in Materials-,
Geo- and Environmental Sciences. One of the
outstanding
techniques
associated
to
synchrotron radiation sources is x-ray absorption
spectroscopy (XAS). XAS spectroscopy has
been demonstrated to be essential to progress
in many scientific fields as it provides, by taking
advantage of its highly-flexible experimental
capabilities, the knowledge of the local atomic
structure of a selected atomic species in the
material under study.
Over the last years we have seen the
development of the so called third generation
sources. One of the main challenges within the
new facilities connected to XAS is the extension
of the available high-energy range. Indeed, the
use of XAS as a dedicated tool to determine
local structural environments has previously
been confined to absorption edges below 30
keV. Recent works have demonstrated that it is
possible to measure XAS spectra with
sufficiently high signal to noise ratios in the
1
energy range 30 to 90 keV .
Despite the above advantages there are still
only few works dealing with high-energy XAS
and most of them still deal with qualitative and
fingerprint analyses. The main reason for this
lack of experimental work seems to be linked to
the assumption that the finite lifetime of the corehole smears out dramatically the spectral
features so as to avoid structural determination,
and that this effect becomes more serious for K2
absorption edges of heavier elements .
In this work we present the first quantitative
analysis made on the x-ray absorption nearedge structure (XANES) region at the Nd K-edge
in natural minerals containing Nd in trace
concentrations. Among the rock forming
minerals, aluminosilicate garnets (X3Y2Si3O12,
X=Fe2+, Mn2+, Mg, Ca) are intensly studied both
due to the complexity of their crystal chemistry
and to theirstability over a wide range of
3
physico-chemical parameters . Garnets in lower
crustal mafic and ultramafic rocks usually
contain rare-earth elements (REE) in trace
concentrations. The diffusion coefficients of REE
between garnets and the coexisting phases are
used to interpret the crystallization and
metamorphic history of crustal rocks. An
understanding of REE diffusion in garnets
cannot be obtained without a characterization of
their
structural
behavior.
Despite
their
geochemical importance, a direct crystal
chemistry characterization of REE at trace levels
in natural garnets is not available in literature
because of the difficulty of obtaining structural
information on elements present in so low
concentration by means of conventional
diffraction methods.
The goal of this work is twofold. On the one
hand we provided an exact structural
determination about which is the position that Nd
enters in the complicated mineral framework. On
the other hand we demonstrate the capability of
the XANES technique to solve different
structural environments, being this capability not
affected by the damping and broadening of the
signal due to the short lifetime of the excited
atomic state.
We have studied the local environment of Nd
at trace levels in a series of natural garnets
belonging to the pyrope-grossular solid-solution
and containing different Nd concentrations (1761029 ppm). The samples are melanite garnets
occurring in carbonatitic rocks and labelled
A204, V19 and 89/35. Samples exhibit different
Nd concentration, as determined by ionic
microprobe analysis, being 1029, 344 and 176
ppm for A204, V19 and 89/35 respectively. The
chemical compositions of the A204, V19 and
89/35 samples are respectively:
X:(Ca2.91Mg0.04Mn0.02Na0.03)Y:(Mg0.10Ti0.89Zr0.04
3+
3+
Al0.28Fe 0.69) Z:(Si2.34Fe 0.66)O12
(Ca2.89Mg0.05Mn0.02Na0.04)(Mg0.08Ti0.83Zr0.03Al0.20
3+
3+
Fe 0.86)(Si2.47Fe 0.53)O12
(Ca2.97Mg0.03Mn0.03Na0.01)(Mg0.09Ti0.49Zr0.02Al0.26
3+
3+
Fe 1.14)(Si2.66Fe 0.34)O12
with trace concentrations of Ce of 755, 257 and
159 ppm, respectively.
XAS measurements at the commonly used Nd
L3-edge (~6208 eV) are unattainable in these
samples, due to the presence of interfering
fluorescence lines from the matrix and by the
presence of the Ce L2-edge (6164 eV) close to
the Nd L3-edge, with a Ce concentration similar
to that of Nd. These problems can be overcome
by use of the Nd K-edge (~ 43570 eV), since at
this energy there are no problems of overlapping
of absorption edges and fluorescence lines. This
problem illustrate the significant interest of XAS
into the possibility of working at high energy.
The Nd K-edge spectra were collected at 77 K
in transmission mode on the reference
compound Nd(OH)3, and in fluorescence mode
on powdered samples of the three natural
garnets at the ESRF GILDA BM8 CRG
beamline. The energy resolution was about 5.4
eV at 43.5 keV.
Figure 1 reports the raw Nd K-edge XAS
spectra for the three garnets under study. The
XAS oscillations are clearly visible above the
edge. Therefore, the Nd K-edge XANES spectra
can be used to perform a quantitative
determination of the local environment of trace
Nd in these garnets. The comparison of the
XANES region indicates also that the structural
55
environment of Nd is the same for the three
garnets.
not only validates this result, but also shows
convincely that the structural determination is
not affected by the damping and broadening of
the signal due to the short lifetime of the excited
atomic state.
Figure 1. Detailed comparison of the Nd K-edge XANES
region for the 3 garnets under study.
The computation of the Nd K-edge absorption
cross-section was carried out using the multiplescattering CONTINUUM according to standard
4
FMS methods . The Coulomb part of each
atomic potential was generated using charge
densities for neutral atoms. The atomic orbitals
were chosen to be neutral for the ground state
potential, whereas we follow the Z+1 rule to
build the excited state potential. Finally, an
appropriate exchange and correlation (ECP)
potential was added to the Coulomb part of the
input potential.
Initially, we have considered two different
possibilities for the position that trace Nd enters
in the X3Y2Si3O12 garnet structure. Hence, we
have built-up two class of clusters assuming that
Nd enters the dodecahedral X-site and the
octahedral Y-site, respectively. The calculations
performed by using a real Hedin-Lundqvist ECP
spectra reproduce all the features present in the
experimental spectra, their relative intensity and
their relative energy separation. After taking into
account the effect of the core-hole lifetime (17.3
eV) and the experimental resolution, the
agreement between the computation and the
experimental XANES is remarkable. Figure 2
shows the comparison between the Nd K-edge
XANES spectrum of the garnet with a Nd
content 1029 ppm (A204) and the theoretical
computations performed by assuming that Nd
enters the octahedral and dodecahedral sites. It
should be noted that the energy scale of each
computation is referred to its own muffin-tin
potential so that calculation provides an unique
energy scale to align both X- and Y-site
theoretical spectra. The results of the
computation strongly suggest that trace Nd
enters the dodecahedral X-site. The same
comparison made after convolution of the
theoretical spectra with the full core-hole width
Figure 2. Comparison between the experimental Nd K-edge
XANES signal of A204 and those calculated on the basis of
the FMS theory assuming Nd in the dodecahedral (X-site) or in
the octahedral (Y-site) sites after taking into account the full
Nd K-edge core-hole width.
Summarising, the study of the high-energy Kedge x-ray absorption of Nd occurring in trace
concentrations in natural garnets demonstrates
that Nd enters a structural garnet site and does
not occupy matrix defects. Indeed, Nd enters the
dodecahedral X-site of the X3Y2Si3O12 garnet
structure and does not substitute Al at the
octahedral Y-site. Therefore we provide a direct
crystal chemistry characterization of rare-earths
elements at trace levels in natural garnets not
available in literature. Moreover, the capability of
high-energy XANES as powerful structural tool
providing structural details unattainable by using
standard methods has been demonstrated.
Principal publication
J. Chaboy, E. Cotallo, S. Quartieri, F. Boscherini. J.
Synchrotron Rad. 2002, 9, 86
Acknowledgements
This work was partially supported by the Aragón DGA
(P0004/2001), Spanish DGICYT (MAT99-0667-C0404) grants.
References
1
M. Braglia, G. Dai, S. Mosso, S. Pascarelli, F.
Boscherini, C. Lamberti. J. Appl. Phys. 1998, 83, 5065.
2
D. G. Stearns. Philos. Mag. B 1984, 49, 541.
3
W. van Westrenen, J. Blundy, B. Wood. Amer.
Mineral. 1999, 84, 838.
4
J. Chaboy, S. Quartieri. Phys. Rev. B 1995, 52, 6349.
5
S. Quartieri, J. Chaboy, G. Antonioli, C. A. Geiger.
Phys. Chem. Minerals 1999, 27, 88.
56
PRESSURE-INDUCED THREE-DIMENSIONAL FERROMAGNETIC CORRELATIONS IN THE
GIANT MAGNETOCALORIC COMPOUND Gd5Ge4
C. Magén, L. Morellón, P. A. Algarabel, M. R. Ibarra
phase-segregated O(II) + O(I) state is found at
low temperatures.
The aim of this work is to investigate the
possibility to induce three-dimensional (3D)
ferromagnetic correlations in Gd5Ge4 upon
application of an external hydrostatic pressure.
In Fig. 1 we display the linear thermal
expansion (LTE) of Gd5Ge4 at different values of
the applied hydrostatic pressure. Upon
application of pressure, a distinct anomaly
develops in the LTE curve and a clear jump is
detected at higher pressure values. According to
our investigation of the magnetoelastic behavior
of this compound 13, this anomaly signals the
existence
of
a
pressure-induced
lowtemperature O(I)–FM phase, the amount of this
phase being reflected in the magnitude of the
jump.
0.0
-3
Linear Thermal Expansion (10 )
-0.5
-1.0
1 kbar
-1.5
1.000
-2.0
2.6 kbar
-2.5
5.9 kbar
∆V/V
Gd5(SixGe1-x)4 is a unique class of materials
where many interesting properties and intriguing
1
behavior have been recently discovered . The
unprecedented giant magnetocaloric effect 2,
3,4
, and giant
strong magnetoelastic effects
5,6
magnetoresistance
can be highlighted as the
most relevant. This phenomenology has been
associated with the intrinsically layered
crystallographic structure combined with a
magnetic-martensitic
first-order
phase
7
. The coupled magnetictransformation
crystallographic transition can be induced
reversibly by the change of external parameters
such as temperature or external magnetic field
1,4
. Therefore, these alloys are attractive for their
potential applications in magnetic refrigeration
and/or as magnetostrictive/magnetoresistive
transducers.
Three extended solid solution regions exist in
the temperature-composition (T–x) phase
8,9
diagram : the Si-rich solid solution, 0.575≤x≤1,
has the orthorhombic Gd5Si4-type structure
[O(I)]; the intermediate phase 0.4<x≤0.503 has a
room temperature monoclinic (M) structure; and
the Ge-rich region, 0<x≤0.3 crystallizes in the
Gd5Ge4-type structure [O(II)]. All three structures
are composed of identical two-dimensional (2D)
sub-nanometer-thick
layers
(slabs)
interconnected via partially covalent inter-slab
X–X bonds (X = Si, Ge). In the O(I) structure, all
the slabs are interconnected by X–X bonds; half
of these bonds are broken in the M structure and
none remain in the O(II) structure. The
magnetic-crystallographic transition involves
breaking/reforming specific covalent X–X bonds
7
and the low-temperature ground state for all
compositions 0<x≤1 is always ferromagnetic
(FM) with all the slabs being interconnected, i.e.
with the O(I) structure. The M structure is always
paramagnetic (PM) whereas the O(II) can
support either PM or antiferromagnetism (AFM)
4,9
. The magnetic behavior of the R5(SixGe1-x)4
compounds can be understood qualitatively in
terms of competition between intralayer (within
the 2D slabs, conventional indirect 4f-4f RKKY)
and interlayer exchange interactions (between
slabs, direct Gd-Si/Ge-Gd superexchange
propagated via the X-X bonds) 1,10.
In sharp contrast with the magnetic behavior
of the Ge-rich compounds no FM phase is
observed in Gd5Ge4 in zero magnetic field and
down to the lowest measured temperature 11,12.
Gd5Ge4 orders antiferromagnetically at ∼ 130 K,
this system presenting a very complex magnetic
field-temperature (H–T) phase diagram and an
interesting magnetoelastic behavior 13. A fully
irreversible field-induced O(II) (AFM) → O(I)
(FM) transformation takes place below ≈ 10 K,
this becoming fully reversible above ≈ 20 K.
Between ≈ 10 K and ≈ 20 K the field-induced
transition is partially reversible and a spatially
0.995
0.990
295 K
0.985
0.980
-3.0
100 K
20 K
0.975
0 2 4 6 8 10 12 14
8.1 kbar
P (kbar)
10.9 kbar
-3.5
-4.0
0
25
50
75
100
Temperature (K)
125
150
FIG. 1. Linear Thermal Expansion as a function of temperature
under selected values of the applied hydrostatic pressure. In
the inset the relative change in volume of the sample at
selected temperatures is displayed.
In order to correlate the structural behavior
with the magnetic properties we have carried out
a systematic study of the magnetism of Gd5Ge4
as a function of temperature, applied magnetic
field and applied hydrostatic pressure. In Fig. 2
we display the temperature dependence of the
magnetization in an applied field of 500 Oe at
selected values of the applied hydrostatic
pressure: 0, 1.3, and 8 kbar. As expected 11-13,
at ambient pressure no FM state is detected
down to 5 K (open circles) but application and
removal of 50 kOe at 5 K induces a FM state
that remains up to ≈ 14 K (open squares). As is
clearly seen in Fig. 3, an applied hydrostatic
pressure of 1.3 kbar is sufficient to induce a FM
signal at ≈ 35 K (heating), the value of which at 5
K is much lower than that obtained when
applying and removing 5 T at ambient pressure.
Therefore, from this and the results in Fig. 1, we
can interpret this data supposing that the sample
volume at 1.3 kbar is spatially phase segregated
into O(II)–AFM and O(I)–FM regions, i.e. 1.3
kbar is sufficient to enhance the interlayer
interactions favoring 3D FM correlations. As far
as we know, this is the first time phaseseparation phenomena have been observed in a
57
20
Magnetization (emu/g)
TC
1.3 kbar
10
8 kbar
TN
0 kbar
H = 500 Oe
dc
0
25
50
80
60
40
20
0
2
4
6
8
Pressure (kbar)
10
12
FIG. 3. Percentage of pressure-induced O(II)-FM phase as
estimated from LTE results (open circles) and magnetization
measurements (solid circles). The line is a guide for the eye.
15
0
100
0
after applying and removing 50 kOe at 5 K
5
Pressure-induced O(I)–FM phase (%)
pure 4f localized-moment system upon
application of hydrostatic pressure. If we apply
and remove isothermally a magnetic field of 50
kOe at 5 K and 1.3 kbar, a full FM signal is
recovered (solid squares). Should this physical
picture be correct, a higher pressure should
increase the relative volume of the O(I)–FM
regions. This is indeed the case since the FM
signal at 8 kbar is almost maximum. We
therefore propose that a hydrostatic pressure of
8 kbar is able to induce a O(I)–FM ground state
in the majority of the sample with a TC ≅ 65 K
(heating).
75 100 125
Temperature (K)
150
175
FIG. 2. Magnetization in an applied field of 500 Oe as a
function of temperature under selected values of the applied
hydrostatic pressure. Black arrows indicate the direction of
temperature change.
The relative percentage of the pressureinduced O(I)–FM phase can be estimated from
magnetization measurements. The final values
are displayed in Fig. 3 (solid circles) together
with the results obtained from the LTE data, see
Fig. 1, assuming that the jump in the LTE at 10.9
kbar corresponds to a 100% of O(I)-FM
transformed phase at low temperatures. As can
be seen the results are in very good agreement,
this being a strong evidence of the physical
picture presented to interpret the LTE and
magnetization results as a function of pressure.
From the results in Fig. 3 we can be quite
confident that at pressures above ≈ 10 Kbar the
entire volume of the sample at low temperatures
below TC (10 Kbar) ≅ 53 K is FM crystallizing in
the O(I) structure.
In conclusion, we have explored the
possibility
to
induce
3D
ferromagnetic
correlations in the giant magnetocaloric alloy
Gd5Ge4 by means of LTE and magnetic
measurements at different applied pressures. As
a main result, application of hydrostatic pressure
induces a spatially phase-segregated ground
state where O(I)–FM and O(II)–AFM regions
coexist within the sample volume. It has been
predicted that at pressures of over 10 kbar, the
low-temperature O(I)–FM ground state is
stabilized in the entire sample volume.
We propose a physical picture where the
effect of pressure is to reduce the interatomic
distances, thus enhancing the interlayer
interactions in this naturally nanolayered
material. This should favor the formation of
specific covalent bonds, inducing a first-order
pressure-induced
magnetic-crystallographic
transformation from an O(II)–AFM to an O(I)–FM
structure.
Main publication
C. Magén, Z. Arnold, L. Morellón, Y. Skorokhod, P. A.
Algarabel, M. R. Ibarra, J. Kamarad. Phys. Rev. Lett.
2003, 91, 207202.
Acknowledgements
The finantial support of Grant No. MAT2000-1756 is
acknowledged.
References
1
V. K. Pecharsky, K. A. Gschneidner, Jr. Adv. Mater.
2001,13, 683.
2
V. K. Pecharsky, K. A. Gschneidner, Jr. Phys. Rev.
Lett. 1997,78; Appl. Phys. Lett. 1997, 70, 3299; J.
Magn. Magn. Mater. 1997, 167, L179.
3
L. Morellón et al. Phys. Rev. B 1998, 58, R14721.
4
L. Morellón et al. Phys. Rev. B 2000, 62, 1022.
5
L. Morellón et al. Appl. Phys. Lett. 1998, 73, 3462; J.
Magn. Magn. Mater. 2001, 237, 119.
6
E. M. Levin, V. K. Pecharsky, K. A. Gschneidner, Jr.
Phys. Rev. B 1999, 60, 7993.
7
W. Choe et al. Phys. Rev. Lett. 2000, 84, 4617.
8
V. K. Pecharsky, K. A. Gschneidner, Jr. J. Alloys
Comp. 1997, 260, 98.
9
A. O. Pecharsky et al. J. Alloy Comp. 2002, 338,
126.
10
E. M. Levin, V. K. Pecharsky, K. A. Gschneidner Jr.
Phys. Rev. B 2000, 62, R14625.
11
E. M. Levin, K. A. Gschneidner, Jr., V. K.
Pecharsky. Phys. Rev. B 2001, 65, 214427.
12
E. M. Levin et al. Phys. Rev. B 2001, 64, 235103.
13
C. Magén et al. J. Phys. Condensed Matter 2003,15,
2389.
58
SUPERCONDUCTING PROPERTIES OF METAL/MgB2 COMPOSITE WIRES
E. Martínez, L. A. Angurel, A. Millán, R. Navarro
The development of materials with the new
1
MgB2 superconductor , which has critical
temperatures of Tc=39 K, has opened great
expectations. This is because it is a suitable
candidate for large-scale electrical applications
such us magnets for Magnetic Resonance
Imaging, transformers, motors, generators…
operating in the range of 20-30 K, easily
reachable with cryocoolers.
A key support of this interest arose from the
conformation of long metal/MgB2 composite
wires and tapes with high critical currents
densities (Jc=109-1010 A/m2) using well-known
powder-in-tube (PIT) methods. Because its
potential scalability and production flexibility,
these
technologies
are
attractive
and
inexpensive for long-wire fabrication.
Jc, which is the maximum current per unit
area that the superconductor wire can carry
without energy losses, is one of the most
important parameters for the characterisation of
such conductors. Jc decreases under applied
magnetic fields, B, reducing to zero at a value
called irreversibility field, Birr.
Currently, MgB2 materials have relatively low
Birr values (4-6 T at 20 K), hence special efforts
are being made to improve the superconducting
behaviour under high fields. Some groups have
reported improvements of the Jc(B) dependence
by neutron irradiation of the samples 2, by using
3
ball-milled powders and by doping with nanoparticles (10-30 nm) such as SiC 4 and
5
diamond .
In the PIT technique, mixtures of unreacted
Mg and B powders, the so called in situ reaction
approach; or pre-reacted MgB2 powders, ex situ
reaction technique, are packed inside metal
tubes (in our case, typically of 4.0 mm outer
diameter and 2.5 or 3.0 mm inner ones).
Subsequently the tubes are cold drawn in round
dyes down to 1.2 mm of diameter in 0.1 mm
reduction steps. The final wires have core
diameters of 0.6 or 0.8 mm, depending on the
initial inner diameter of the tubes. Finally the
wires are annealed in argon, to prevent
oxidation, in order to react (in situ) or sinter (ex
situ) the core precursors.
The selection of adequate sheaths for these
composites, giving thermal, electrical and
mechanical stability, constitutes nowadays an
open issue to be addressed prior to reach
technologically useful metal/MgB2 conductors.
Different metal sheaths have already been used:
Fe, Cu, Ni, Ag, Cu-Ni alloys and stainless steel
(SS), as well as different metal combinations
such as: (from outside to inside) Cu/Ta and
SS/Cu/Fe (for a review see for instance 6). Up to
now, the highest Jc(B,T) values are obtained
with hard metal sheaths that do not react with
Mg or MgB2, such as steel and iron, but these
wires, as consequence of a poor thermal
stability, easily transit to normal state (quench)
at Jc > 109 A/m2. Moreover, silver sheathed wires
present very poor results compared with copper
or nickel sheathed wires and therefore have
been disregarded.
Here, we report on the superconducting
properties of Cu- and Ni-sheathed MgB2 monofilament wires fabricated in the ICMA by the PIT
technique using the in situ and ex situ
procedures, respectively. Both are interesting
sheath candidates due to their properties of
ductility,
soldability
and
good
thermal
conductivity.
Figure 1: Longitudinal SEM images of (a) ex situ Ni/MgB2 wire
annealed at 850 ˚C during 0.5 h; and (b) in situ Cu/MgB2
annealed at 700 ˚C during 0.5 h. The circle in b) indicates the
main phase containing MgB2.
A typical SEM longitudinal cross-section of
Ni/MgB2 and Cu/MgB2 composite wires after
annealing is shown in Figure 1. In both cases
the superconducting cores have irregular shape.
This is partially produced during mechanical
conformation because the lower hardness of the
sheath with respect to the precursors
(particularly, boron and MgB2), but it would be
also due to the reactivity of the precursors from
the core with the inner sheath wall during the
heat treatment.
A
reaction
layer
adjacent
to
the
superconducting core, with darker contrast and
20 to 30 µm thickness, is observed for both
wires. EDX and X-Ray analyses have indicated
that this layer corresponds to MgNi2 and MgCu2
while the rest of the sheath remains pure nickel
59
and copper, respectively. Nevertheless, the ex
situ Ni/MgB2 wires presents more homogeneous
microstructures than the Cu-sheathed ones,
which also show MgCu2 grains homogeneously
dispersed inside the core, with sizes typically
ranging from 20 to 80 µm.
x=0.2, 700ºC, 18min
x=0, 700ºC, 30min
x=0.2, 700ºC, 18min, q
1010
Cu/MgB
2
in situ
2
(A/m )
109
J
C,M
108
(a)
107
0
1
MgB
10
10
9
10
8
10
7
2
3
B (T)
4
5
MgB (SiC)
2
1.8
0.1
Ni-sheated
ex situ
5K
J
C,M
2
(A/m )
10
5K
20 K
of the in situ reaction originally used in [4],
8
2
obtaining Jc,M>10 A/m for B<3.7 T at 20 K.
The superconducting behaviour of Nisheathed wires shows that nickel may be a
valuable alternative to iron for practical
applications. Nevertheless, non-magnetic Ni
based alloy would be preferable. Moreover, it
has to be noted that Ni would not be suitable
with in situ procedures because of the important
reactivity of Mg and Ni. Therefore, doping would
require either the ex situ method or the use of
diffusion barriers between the core and the Ni
sheath.
The lower performance of Cu/MgB2 wires
would be due to the in situ reaction it-self and to
the reactivity between the Cu sheath and the Mg
precursors together with the insufficient
hardness of copper. Nevertheless, main
advantages of these MgB2/Cu wires are certainly
related to the good thermal stability given by the
high thermal conductivity of the sheath. This
allows carrying out transport measurements up
to high currents (500-700 A at 15-20 K) without
quenching, even without surrounding cryogenic
liquid or gas to thermalise the sample, which is
very unlikely on wires with others sheaths such
as iron, stainless steel, nickel, etc.
Our future efforts are focused in the search
of conductors thermally stable and with high
performance at fields between 5 to 10 T, both
necessary for technical applications.
0
(b)
1
20 K
30 K
2
B(T)
3
4
5
Figure 2. Magnetic field dependence of the critical current
density, Jc,M(B), estimated from the M-B hysteresis loops at
different temperatures for the Cu- (a) and Ni-sheathed wires
(b) annealed at 850 ºC during 0.5 h. ‘q’ in (a) means quenched
at room temperature.
The field dependences of the critical current
density estimated form the magnetization
hysteresis curves, Jc,M(B), are shown in Fig. 2.
Note that for these wires, Jc values of 109 A/m2
would correspond to currents of 500-600 A.
Ni-sheathed wires show a superconducting
behaviour better than Cu ones, having higher Jc
values and less sharp Jc(B) decays. This way,
8
2
Jc,M decreases down to 10 A/m for magnetic
fields of 3 and 2 T at 20 K, for the Ni- and Cusheathed wires, respectively.
For the same sheath material, the annealing
conditions only affect the Jc values but not their
field dependence, indicating that these
parameters, for the used range here, do not
change the pinning mechanisms. For the Cusheathed wires, it has been observed that an
excess of Mg over the stoichiometric proportions
(x in fig. 2-a, given in atom.%) results in an
improvement of Jc by the increase of the amount
of superconducting phases
From our results (Fig. 2-b), it is clear that
doping with SiC nano-particles (20 nm average
size) is also effective in improving the Jc(B)
decays when using the ex situ procedure instead
Principal publications
E. Martínez, L. A. Angurel, R. Navarro. Supercond.
Sci. Technol. 2002, 15, 1043
E. Martínez, A. Millán, R. Navarro. European
Conference of Applied Superconductivity, EUCAS,
2003.
Acknowledgements
The financial support of the Spanish CICYT projects
MAT-1999-1028 and MAT-2002-04121-C03-02 is
acknowledged.
References
1
J. Nagamatsu, N. Nakagawa, T. Murakanaka, Y.
Zenitani. Nature 2001, 410, 063.
2
M. Eisterer, B. A. Glowacki, H. W. Weber, L. R.
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2002, 15, 1088.
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R. Flükiger, P. Lezza, C. Beneduce, N. Musolino, H.
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4
S. H. Zhou, A. V. Pan, M. J. Qin, H. K. Liu, S. X. Dou.
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C. H. Cheng, H. Zhang, Y. Zhao, Y. Feng, X. F. Rui,
P. Munroe, H. M. Zeng, N. Koshizuka, M. Murakami.
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R. Flükiger, H. L. Suo, N. Musolino, C. Beneduce, P.
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60
PHOTO-INDUCED CHIRALITY ON ACHIRAL SIDE CHAIN LIQUID CRYSTALLINE
POLYMETHACRYLATES
L. Oriol, M. Piñol, R. M. Tejedor, J. L. Serrano, R. Alcalá, F. J. Rodríguez, B. Villacampa
N
N
CN
n= 2 PC2; n= 6 PC6; n= 10 PC10
O
C O-(CH2)2-O
N
0.5
O
C O-(CH2)6-O
N
0.5
N
CN
N
OCH3
PC2/POMe-50
O
C O-(CH2)6-O
N
N
0.1
O
C O-(CH2)6-O
0.9
CN
CN
PC6/PBp-10
Figure 1
In order to study in deep the relationship
between molecular structure, Tg and azocontent on the photoinduction of chirality, thin
films of polymers shown in Figure 1 have been
irradiated with circular polarized light and the
chirooptical properties were examined by
circular dichroism and polarimetry. The films
were previously annealed at the mesophase
temperature.
0
2000
The CD spectra of these films are gathered in
Figure 2.
Ellipticity mdeg
We have synthesized different series of
polymers having a cianoazobenzene derivative
as
photoaddressable
group
for
optical
14
or
applications, such as holographic storage
15
non linear optics . Some of these materials are
gathered in Figure 1.
O
C O-(CH2)n-O
PC2
PC6
PC10
PC2/POMe-50
-2000
Azobenzene side-chain liquid crystalline
polymers
(azo-SCLCPs)
have
received
considerable attention as promising materials in
the field of photonics, i.e. holographic storage,
optical switching, or as light-driven aligning
1
layers of liquid crystals . All these applications
derive from the possibility of changing the
orientation of the azobenzene chromophores
through
the
photoinduced
trans-cis-trans
isomerization of azobenzene units. The
irradiation is usually carried out with linearly
polarized light giving rise to a reorientation of the
azo chromophores perpendicular to the laser
polarization direction. Furthermore, in the case
of azo-SCLCPs, annealing in the dark at
mesophase temperatures leads to an increasing
of the birefringence (thermotropic effect).
Nevertheless,
the
heating
above
the
isotropization temperature as well as irradiation
with circular polarized light erases the written
information.
On the other hand, helical arrangements on
macromolecules are recently object of intense
research because of the scientific curiosity on
nature-imitating macromolecules and their
2,3
predicted technological applications . In this
sense, the control of heliticity arises as an
aspect of crucial importance on the development
of helical polymeric devices. Chiroptical
properties on azopolymers have been usually
induced by introduction of stereogenic centers
on the macromolecular structure4,5. For these
polymers, the prevailing chiral geometry of the
chromophores along the macromolecular
backbone
determines
the
extent
and
handedness of the resulting supramolecular
helicity. However, Nikolova et al. 6 have recently
described the photoinduction of large circular
anisotropy in films of an achiral mesogenic
azopolyester on illumination with circularly
polarized light (CPL) or amorphous polymers but
7illuminated with elliptically polarized light (EPL)
10
. Furthermore, a reversible chiroptical
switching has been described for these
azopolymers11, which suppose a control of the
photoinduced
enantiomeric
supramolecular
structure in the material. Unusual effects are
recently described on these materials as the
switch of the sense of circular anisotropy during
12
photofabrication of
irradiation , or the
superhelix-like patterns using a conventional
holographic optical set-up13.
PC6/PBf-10
200
300
400
500
600
Wavelength nm
61
Several conclusions can be drawn from these
results. Firstly, there is an important effect of the
length of the flexible spacer on the chiroptical
properties. The hexamethylenic spacer provides
an adequate flexibility to the polymer and a
relatively high Tg, giving rise to a huge ellipticity.
Secondly, the incorporation of a low percentage
of azo groups on mesogenic copolymers can
induce
the
organization
of
the
nonphotoaddressable, mesogenic side groups in a
supramolecular chiral structure. Furthermore,
the photoinduced supramolecular helix could be
easily switched by irradiating with circular
polarized light with opposite handness.
14
C. Sánchez, R. Cases, R. Alcalá, A. López, M.
Quintanilla, L. Oriol, M. Millaruelo. J. Appl. Phys. 2001,
89, 5299.
15
F. Rodríguez, J. Sánchez, B. Villacampa, R. Alcalá,
R. Cases, M. Millaruelo, L. Oriol. Polymer 2004, 45,
2341.
The proposed model for explaining this optical
behavior considers the polymeric films
consisting of many layers. The presence of an
optical axis in the first layer (intrinsically present
on the liquid crystalline domains or induced by
linear polarized light in amorphous materials)
determines that CPL passing through the first
layer is transmitted to the second layer as EPL.
Consequently, molecules of the second layer
reorient perpendicular to the long axis of the
polarization ellipse and changes the azimuth of
the polarization transmitted to the next layer.
The overall effect is the formation of a
supramolecular helical structure in which a
cooperative effect is produced between light and
mesogens in which a rotation of light is induced
by mesogens as well as the light induced a
rotation of mesogens.
Acknowledgements.
The support from the CICYT under Project MAT200204118-C02 is gratefully acknowledged.
References
1
A. Natansohn, P. Rochon. Chem. Rev. 2002, 102,
4139.
2
M. Masuda, P. Jonkheijm, R. P. Sijbesma, E. W.
Meijer. J. Am. Chem. Soc. 2003, 125, 15965.
3
J. H. K. K. Hirschberg, L. Brunsveld, A. Ramzi, J. A.
J. M. Vekemans, R. P. Sijbesma, E. W. Meijer. Nature,
2000, 407, 167.
4
E. Yahima, J. Noguchi, Y. Okamoto. Macromolecules
1995, 28, 8368.
5
L. Angiolini, D. Caretii, L. Giorgini, E. Salatelli.
Macromol. Chem. Phys 2000, 201, 533.
6
L. Nikolova, T. Todorov, M. Ivanov, F. Andruzzi, S.
Hvilsted, P. S. Ramanujam. Opt. Mater. 1997, 8, 255.
7
L. Nikolova, L. Nedelchev, T. Todorov, T. Petrova, N.
Tomova, Y. Dragostinova. App. Phys. Lett. 2000, 77,
657.
8
M. Ivanov, I. Naydenova, T. Todorov, L. Nikolova, T.
Petrova, N. Tomova, V. Dragostinova. J. Mod. Opt.
2000, 47, 861.
9
L. Nedelchev, L. Nikolova, T. Todorov, T. Petrova, N.
Tomova, V. Dragostinova, P. S. Ramanujam, S.
Hvilsted. J. Opt. A: Pure Appl. Opt. 2001, 3, 304.
10
M. J. Kim, B. G. Shin, J. J. Kim, D. Y. Kim. J. Am.
Chem. Soc. 2002, 124, 3504.
11
G. Iftime, F. Lagugné-Labarthet, A. Natansohn, P.
Rochon. J. Am. Chem. Soc. 2002, 122, 12646.
12
D. K. Hore, A. Natansohn, P. J. Rochon. J. Phys.
Chem. B 2003, 107, 2506.
13
M. J. Kim, J. Kumar, D. Y. Kim. Adv. Mater. 2003,
15, 2005.
62
CHIRAL HELICAL INDUCTION THROUGH H-BONDING IN SUPRAMOELCULAR
POLYMERS
J. Barberá, L. Puig, J. L. Serrano, T. Sierra
a)
H
N
N
H
The significant role of helical organizations in
nature (i.e. α-helical proteins, nucleic acids,
Tobacco Mosaic Virus) has stimulated the
curiosity of researchers in materials chemistry.
Many interesting examples aimed at building
and
controlling
supramolecular
chiral
architectures based on helical superstructures
have been reported 1,2. Indeed, interesting linear
3
and nonlinear optical properties 4,
optical
electrooptical behavior 5,6, energy transfer 7, etc.
have been found in synthetic helical
superstructures, which are often prepared
according to the principles of supramolecular
chemistry 8.
We have developed an efficient strategy based
on two types of non-covalent intermolecular
interaction, i.e. π-π interactions and H-bonding,
which have enabled the construction of a
number of supramolecular liquid crystalline
9
assemblies . Our approach consists on merging
mesomorphic arrangements based on molecular
stacking, promoted by π-π interactions of simple
molecules, and the possibility of anchoring the
structure of the mesophase using H-bonding
interactions with a second type of molecule. In
this way we should be able to build up stable
helical polymeric assemblies in which chirality
can be induced via a stereogenic center and
transferred to the mesophase through hydrogenbonding. The final supramolecular organization
must be endowed of a one-dimensional helical
10
arrangement along the column .
For this purpose, we have chosen molecular
units that are capable of organizing into
columnar mesophases, by virtue of a disk-like
promesogenic structure, and can also participate
in intermolecular hydrogen-bonding interactions.
We therefore decided to employ 2,4,6triarylamino-1,3,5-triazines (figure 1a). It is also
necessary to introduce chirality into the system
and for this purpose we have selected R-3methyladipic acid as a chiral clip (figure 1b). It
was envisaged that this diacid would not only fix
the supramolecular organization by building a
polymeric-like structure but would also be able to
imprint its chiral character onto the resulting selfassembled structure.
N
N
N
N
N
N
H
H
N
N
H
b)
MeAdip
O
N
C
N
H O
H
CH3
*
O H
O
Tri-2OC10
c)
d)
Tri-2OC10/MeAdip [1:1]
Tri-2OC10/MeAdip [2:1]
Figure 1. a) Molecular structure of the triazine derivative
(peripheral tails are omitted for the sake of clarity) b) Molecular
structure of (R)-3-methyladipic acid. c and d) Idealized cartoon
representation of the structure for two supramolecular
materials prepared with different proportions of (R)-3methyladipic acid.
The use of techniques such as x-ray diffraction
and circular dichroism in the mesophase allow to
confirm the success of the design. A reflection
maximum corresponding to a periodic distance
within the column appears in the x-ray diffraction
patters of these supramolecular materials,
especially those containing A regular stacking
within the columns is, indeed, induced by the
presence of R-3-methyladipic acid molecules
fixing distances between disks by means of
hydrogen
bonding.
Moreover,
additional
experiments with adipic acid have led to the
conclusion that the methyl group in the
stereogenic center of the R-(3)-methyladipic acid
performs a twofold role in the supramolecular
organization. Firstly, it must provide the acid a
bent conformation that favors the possibility of
interdisk association along the column, which
helps to keep the columnar arrangement (figures
1b and 1c). Secondly, it is responsible of the
transfer of chirality to a helical superstructure
within the column, which is detected by circular
dichroism experiments (figure 2). CD spectra
recorded in the mesophase demonstrate that
there is a formal optical activity due to a helical
superstructure biased towards a chiral sense
that is determined by the configuration of the
stereogenic center. This optical activity
disappears when the material reaches its
transition temperature to the isotropic state.
63
Abs.
Intensity / mdeg
10
2.5x10-5 in hexanes
isotropic state (80 C)
mesophase (25 C)
mesophase (25 C) after 24 h
5
0
Tri-2OC10/Adip [2:1]
-5
0,80
250
300
350
400
450
λ (nm)
Figure 2. CD spectral comparison of Tri-2OC10/MeAdip[2:1] in
the isotropic liquid (80°C), in solution (10 mm cell, 2.5 x 10-5 M
in hexanes) and in the mesphase, both in the freshly formed
mesophase and after 24 h. The Uv spectrum in the region
under study in the mesophase is shown below the
corresponding CD spectrum.
Acknowledgements
Financial support was provided by MCyT (MAT200307806-C02-01) and DGA.
References
1
N. Tamaoki. Adv. Mater. 2001, 13, 1135.
2
a) J. J. L. M. Cornelissen, A. E. Rowan, R. J. M.
Nolte, N. A. J. M. Sommerdijk. Chem. Rev. 2001, 101,
4039. b) T. Nakano, Y. Okamoto. Chem. Rev. 2001,
101, 4013.
3
J. Lub, P. van de Witte, C. Doornkamp, J. P. A.
Vogels, R. T. Wegh. Adv. Mater. 2003, 15, 1420.
4
a) T. Verbiest, S. van Elshocht, M. Kauranen, L.
Hellemans, J. Snauwaert, C. Nuckolls, T. J. Katz, A.
Persoons, Science, 1998, 282, 913. b) T. Verbiest, S.
Sioncke, A. Persoons, L. Vyklicky, T. J. Katz. Angew.
Chem. Int. Ed. 2002, 41, 3882.
5
C, Nuckolls, R. Shao, W,. G. Jang, D. M. Walba, T. J.
Katz. Chem. Mater. 2002, 14, 773.
6
a) R. Iglesias, J. L. Serrano, T. Sierra, M. R. de la
Fuente, B. Palacios, M. A. Pérez-Jubindo, J. T.
Vázquez. J. Am. Chem. Soc. 1998, 120, 2908. b) J. L.
Serrano, T. Sierra. Chem. Eur. J. 2000, 6, 759.
7
F. J. M. Hoeben, L. M. Herz, C. Daniel, P.
Jonkheijm, A. P. H. J. Schenning, C. Silva, S. C. J.
Meskers, D. Beljonne, R. T. Phillips, R. H. Friend, E.
W. Meijer. Angew. Chem., Int. Ed. 1983, 22, 565.
8
J. M. Lehn. Principles of Supramolecular Chemistry
9
a) U. Beginn. Prog. Polym. Sci. 2003, 28, 1049. b) T.
Kato, N. Mizoshita, K. Kanie. Macromol. Rapid.
c) C. M. Paleos, D.
Commun. 2001, 22, 797.
Tsiourvas. Angew. Chem. Int. Ed. 1995, 34, 1696.
10
J. D. Hartgerink, E. R. Zubarev, S. I. Stupp. Curr.
Opin. Solid. State Mater. Sci. 2001, 5, 355.
64
NOVEL NLO-PHORES WITH PROAROMATIC DONOR AND ACCEPTOR GROUPS
R. Andreu, J. Garín, J. Orduna, R. Alcalá, B. Villacampa
Donor (D)–acceptor (A) substituted organic
molecules with large second-order nonlinear
optical (NLO) properties constitute a topic of
burgeoning interest due to their possible
applications in areas such as frequency doubling
and photorefractive polymers, among others.
These molecules can show large first molecular
hyperpolarizabilities (β), related to an electronic
intramolecular
charge
transfer
excitation
between the ground and excited states of the
molecule, and it has long been recognized that
D-π-A NLO-phores with dominantly aromatic
ground state do not favor electronic polarization
in an applied field, as a result of the decreased
resonance energy upon charge transfer. This led
Marder et al. to design D-π-A systems in which
the loss of aromaticity in one end (D) on charge
separation was offset by a gain in aromaticity in
1
the opposite end (A) . Given the success of this
approach to obtain NLO-phores with high β
values, a great deal of effort has been devoted
to the study of derivatives bearing proaromatic
acceptors.
In this work we report the first systematic
experimental and theoretical study of the
second-order NLO properties of merocyanines
incorporating both a proaromatic donor and a
proaromatic acceptor.
The target merocyanines incorporating an
acyclic spacer (3, 5a and 5b) were prepared by
reaction of 1 with dithiolium salt 2 or aldehydes
4a and 4b, respectively (Scheme 1).
Since the instability of some push-pull
polyenes is a well-known issue, we reasoned
that incorporation of a partially rigidified spacer
could increase the stability of the desired NLOphores. In fact, reaction of compound 6 with 4a
and 4c afforded 9a and 9c, with four and six
double bonds in the spacer, respectively.
Moreover, compound 8, directly analogous to
5b, was prepared (by reaction of 6 with salt 7)
with a view to study the effect of the introduction
of the cyclohexene moiety on the linear and
nonlinear optical properties of these NLOphores.
Relevant
electrochemical
and
optical
characterization data are gathered in Table 1.
Cyclovoltammetric data indicate that oxidation of
the dithiafulvene moiety and reduction of the
thiobarbituric unit (both chemically irreversible
processes) become increasingly easier on
lengthening the π-spacer, indicating a smaller
contribution of the charge-separated form to the
ground state of the longer derivatives.
The second-order NLO properties of the
NLO-phores were determined by EFISH. The
measured µβ0 values, determined using the twolevel model, range from – 9×10-48 esu for 3 to
-48
1350×10 esu for 9c.
S
SMe I
S
2
NaOEt, EtOH ∆
O Et
N
S Me S
N
O
O Et Me S
n
4a, 4b, (4c)
1
EtOH, ∆
O Et
N
S
N
O Et
S
S
3
Me S
Me S
O Et
N
S
N
O Et
n
5a, 5b
BF4
Me S
SMe
Me S 7
Me S
O Et
NEt , pyridine ∆
N
Me S
S
Me
O Et
N
Me
N
Me O Et
S
8
MeMe O NEt
Me S
6
O Et
Me S
4a, 4c
N
piperidine (cat.)
S
toluene ∆
MeMe O NEt
3
n
9a, 9c
a: n = 1; b: n = 2; c: n = 3
Scheme 1. Synthetic approach
Table 1. Redox Potentials (V), Absorption Spectra (nm) and
µβ (10–48 esu) for CH2Cl2 Solutions
compound
Eoxa
Ereda
λmax
µβb
µβ0c
3
1.55
–1.48
403
–12
–9
5a
1.16
–1.00
558
100
60
5b
0.87
–0.85
642
1100
525
8
0.81
–0.96
630
440
221
9a
0.65
–0.81
638
2315
1135
9c
0.48
–0.77
638
2746
1350
a
vs Ag/AgCl, glassy carbon working electrode, 0.1 M TBAPF6,
0.1 V s-1
b
Measured at 1907 nm
c
Calculated using the two-level model.
Inspection of Table 1 reveals that, for the
same type of spacer, µβ0 values increase with
the conjugation path, and that introduction of the
isophorone-derived bridge gives rise to a
decrease of µβ0 when compared to an acyclic
spacer of the same conjugation length (5b and
8). It should be noted that µβ0 for 9c is about
four
times
larger
than
for
DANS
(4,-dimethylamino-4’-nitrostilbene), a common
benchmark for second-order NLO-phores.
65
O H
N
S
S
N
O H
n
S
a: n = 0
b: n = 1
c: n = 2
d: n = 3
10
Figure 1. Theoretically studied compounds.
Table 2. Calculated BLA (Å), Charge on the Dithiole Ring (e)
and µβ0 (10–48 esu) for Model Compounds 10.
a
b
b
charge
µβ0
(calc)b
––
+0.344
–62
10b
–0.029
+0.207
2
10c
–0.040
+0.129
437
10d
–0.043
+0.086
1363
compound
BLA
10a
µ
g
µ
20
e
15
10
5
The most relevant results of the calculations
are gathered in Table 2.
a
25
Dipole moment (D)
Moreover, compound 3 is the only one to show a
small but negative value.
Ab initio and DFT calculations have been
carried out on model compounds 10 (Figure 1) in
order to disclose the role of the proaromaticity of
the end groups on the properties of these NLOphores.
B3P86/6-31G*
HF/6-31G*//B3P86/6-31G*
It can be seen that lengthening the π-spacer
results in an increase of ⏐BLA⏐, together with a
decrease of the charge on the dithiole ring. This
implies that the gain in aromaticity at the end
groups and the contribution of the zwitterionic
limiting form to the ground state of these
molecules are more important for the shorter
derivatives. This is confirmed by the small
negative µβ0 value displayed by compound 3,
implying that µg > µe (where g and e refer to the
ground and excited states, respectively). Its very
weak solvatochromism also suggests that this
molecule is close to the cyanine limit and that,
therefore, lies in region C, according to Marder’s
classification.
Although CPHF calculations correctly
reproduce the observed trend in the µβ0 values
of these NLO-phores, a more intuitive picture of
their NLO properties comes from the two-level
model. In this simplified treatment β ∝ ∆µ×fge/E3,
where ∆µ = µe–µg, and fge and E are the
oscillator strength and the energy of the
intramolecular
charge
transfer
transition,
respectively. On passing from 10a to 10d, TDDFT calculations show an increase in fge and a
decrease in E but, more important, predict a
smooth increase in µg and a steeper increase in
µe. Therefore, ∆µ rapidly increases along this
series and, being negative for 10a, an inversion
in the sign of ∆µ is calculated to occur near 10b
(Figure 2).
0
0
1
n
2
3
Figure 2. Calculated µg and µe values for 10.
This explains the low µβ values calculated
for some dithiole-π-acceptor NLO-phores
incorporating two C=C bonds (n = 1) in the
spacer, a fact that cannot be attributed to a poor
electron-donating ability of the 1,3-dithiole unit. A
comparison of the optical properties of the 1,3dithiole NLO-phores herein reported with those
of the TTF-thiobarbituric series reveals that: a)
lengthening the π spacer in the former series
results in a bathochromic shift, in sharp contrast
to the unusual hypsochromic shift observed with
2
the
TTF
derivatives
,
and
b)
the
4,5-dimethyl-1,3-dithiole unit is a more efficient
donor than the TTF moiety for a given number of
conjugated atoms.
To sum up, the proaromatic character of the
1,3-dithiole group gives rise to high µβ values,
provided long spacers are used; lengthening the
polyenic chain results in large photoinduced
changes in the dipole moment and enhanced
hyperpolarizabilities. The negative µβ value for
the shortest derivative demonstrates the
importance of the zwitterionic form in the
description of its ground state. Experimental and
theoretical results demonstrate that the 1,3dithiole moiety is a more efficient π electrondonor than TTF in dipolar D–π–A NLO-phores.
Principal publication
R. Andreu, J. Garín, J. Orduna, R. Alcalá, B.
Villacampa. Org. Lett. 2003, 5, 3143.
Acknowledgements
MCyT-FEDER (BQU2002-00219) and Gobierno de
Aragón-Fondo Social Europeo (P009-2001 and E39).
References
1
S. R. Marder, B. Kippelen, A. K. Y. Jen, N.
Peyghambarian. Nature 1997, 388, 845.
2
M. González, J. L. Segura, C. Seoane, N. Martín, J.
Garín, J. Orduna, R. Alcalá, B. Villacampa, V.
Hernández, J. T. López Navarrete. J. Org. Chem.
2001, 66, 8872.
66
THE CRYOGENIC CURRENT COMPARATOR, DESIGN TOOLS FOR AN ULTIMATE
PRECISION INSTRUMENT
J. Sesé, A. Camón, C. Rillo
The Cryogenic Current Comparator (CCC)
takes advantage of the ideal properties of
superconductors to perform ultimate precision
measurements in electrical metrology. On one
hand the Meissner effect provides a perfect
magnetic shielding (see fig. 1). On the other
hand the Josephson effects provide with a very
sensitive device, the SQUID, for the
measurement of currents in the pA range.
superconductors. Hence the self-inductances
are effective values different from their nominal
values.
Figure 3: Schematic representation of a CCC coupled to a
SQUID through a superconducting flux transformer.
Figure 1: Simulation used finite element software that shows
how a superconducting enclosure provides a perfect shield for
the magnetic field created by a current circulating in the
overlapping tube.
The CCC (see fig. 2) allows controlling the
ratio of two currents I1/I2=N2/N1 (where N1 and
N2 are integer numbers) with high precision.
Resistance bridges based on the CCC are the
state of the art to perform dc resistance
comparisons at metrological level. They are at
present widely used to transfer the value of the
quantum Hall resistance standard to very stable
1
resistors . More recently, its use for the
accurate amplification of quantized currents, in
the pA range, produced by Single Electron
Tunneling devices, towards the realization of a
quantum current standard, is being investigated
2-4
.
2
First designs were introduced in the 1970s
and it has later been used in national metrology
laboratories around the world. Its application for
the current standard needs to take the
instrument to its limits. Yet, formal guidelines
and analytical tools for the design and of CCCs
were not developed. Therefore the goal at ICMA
was to develop these tools.
Based on this model, analytical tools have
been developed that permit the design of an
optimum CCC. These tools have been checked
with the realization of experiments finding a
good agreement (see fig. 3), even more they
have allowed to discard previous theoretical
work found in the literature 6.
Figure 3: Sensitivity data (circles) obtained from [6], for
CCCs with tape pick-up coils. The data (filled squares) and the
numerical calculation (dashed line) for coil #2 are shown
together with the result, using superconducting tape (filled
triangle) instead of wire.
Principal publications
C. Rillo, J. Sesé, E. Bartolomé, A. Camón, J. Flokstra,
G. Rietveld. Metrologia 2003, 40, 51.
J. Sesé, E. Bartolomé, A. Camón, J. Flokstra, G.
Rietveld, C. Rillo. IEEE T. Instrum. Meas. 2003, 52,
612.
Acknowledgements
Work supported by projects CICYT MAT98-0668 and
STW (The Netherlands).
Figure 2: General view of a CCC
Figure 3 shows the model that takes into
account all shielding effects produced by
References
1
B. Jeckelmann, B. Jeanneret. Rep. Prog. Phys. 2001,
64, 1603.
2
A. Hartland. Conf. Electrom. Meas. BEMC, 1993, 18,
1.
3
Y. de Wilde, F. Gay, F. Piquemal, G. Geneves. IEEE
T. Instrum. Meas. 2001, 50, 231.
4
E. Bartolomé. Ph. D. Thesis, University of Twente,
The Netherlands, 2002.
5
I. K. Harvey. Rev. Sci. Instrum. 1972, 43, 1626.
6
E. T. Frantsuz. Metrologia 1998, 35, 847.
67
68
1.- Estructura del Instituto
Structure of the Institute
69
1.1.- Organigrama
Organizational Chart
JUNTA
INSTITUTO
CLAUSTO
CIENTIFICO
DIRECTOR
GERENCIA
Servicios
Económicos
Administrativos
VICEDIRECTOR
ÁREA QUÍMICAS
VICEDIRECTOR
ÁREA MATERIALES
SERVICIOS
DEPARTAMENTOS
DE INVESTIGACIÓN
ÁREA MATERIALES
DEPARTAMENTOS
DE INVESTIGACIÓN
ÁREA QUÍMICAS
Oficina técnica
RMN
Química de los
Compuestos
Organometálicos
Química de la Coordinación
y Catálisis Homogénea
Espectrometría de
masas
Análisis térmico
Microanálisis
Espectroscopia de Sólidos
Física del Estado Sólido a
Bajas Temperaturas
Magnetismo de Sólidos
Materiales de Interés
Tecnológico
Química Orgánica
Nuevos Materiales Orgánicos
Teoría y simulación de
sistemas complejos
71
1.2.- Dirección
Administration
- Año 2002 / Year 2002:
∗
∗
Director / Director:
Vicedirectores / Deputy Directors:
∗
Gerente / Administrator:
Gascón Alonso, Pablo Javier
Carmona Gascón, Daniel
Lázaro Osoro, Francisco
Miguel Pardo, Mª Elisa de
- Año 2003 / Year 2003:
∗
∗
Director / Director:
Vicedirectores / Deputy Directors:
∗
Gerente / Administrator:
Burriel Lahoz, Ramón
Cativiela Marín, Carlos
Angurel Lambán, Luis Alberto
Miguel Pardo, Mª Elisa de
1.3.- Junta
Institute Council
* Presidente / President:
Burriel Lahoz, Ramón
* Secretaria / Secretary:
Miguel Pardo, Mª Elisa de
* Vocales / Council Members: Cativiela Marín, Carlos
Angurel Lambán, Luis Alberto
Falvello, Lawrence Rocco (Jefe Dpto.)
Tejel Altarriba, Mª Cristina (Jefe Dpto.)
Tejero López, Tomás (Jefe Dpto.)
Orera Clemente, Víctor (Jefe Dpto.)
Rillo Millán, Conrado (Jefe Dpto.)
Algarabel Lafuente, Pedro A. (Jefe Dpto.)
Fuente Leis, Germán Francisco de la (Jefe Dpto.)
Ros Latienda, Blanca (Jefe Dpto.)
Falo Forniés, Fernando (Jefe Dpto.)
Estepa Millán, Luis Carlos (Rpte. Personal Técnico Tit.)
Jiménez Sanz, Ana (Rpte. Bec. y Pers. Doc. no Perm.)
Serrate Donoso, David (Rpte. Bec. y Pers. Doc. no Perm.)
Martínez Martínez, Jesús I. (Rpte. Pers. Cient. UZ)
72
1.4.- Claustro Científico
Scientific Board
∗
∗
Presidente / President:
Secretaria / Secretary:
Alcalá Aranda, Rafael
Algarabel Lafuente, Pedro A.
Alonso Gascón, Pablo Javier
Andreu Solano, Raquel
Angurel Lambán, Luis A.
Ara Laplana, Irene V.
Arnaudas Pontaque, José I.
Arrate Martínez, Mónica
Artigas Álava, Miguel
Badía Majós, Antonio
Barberá Gracia, Joaquín
Bardají Luna, Manuel
Bartolomé Sanjoaquín, Juan
Bartolomé Usieto, Fernando
Baselga Arino, Santiago
Blasco Carral, Javier
Buil Juan, Mª Luisa
Burriel Lahoz, Ramón
Camón Lasheras, Agustín
Campo Ruíz, José Javier
Carmona Gascón, Daniel
Casado Lacabra, Miguel Ángel
Casas del Pozo, José Mª
Cases Andreu, Rafael
Castejón Herrer, Luis
Castro Corella, Miguel
Cativiela Marín, Carlos
Cerrada Lamuela, Elena
Chaboy Nalda, Jesús
Ciria Cosculluela, José C.
Ciria Remacha, Miguel
Ciriano López, Miguel Ángel
Contel Fernández, María
Crespo Zaragoza, Olga
Díaz de Villegas Soláns, Mª Dolores
Díez Moñux, Juan Carlos
Elduque Palomo, Ana Isabel
Esteban Pérez, Montserrat
Esteruelas Rodrigo, Miguel Ángel
Falo Forniés, Fernando
Falvello, Lawrence R.
Fernández Álvarez, Francisco J.
Fernández Novoa, Julio F.
Ferrer Cerra, Joaquina
Floría Peralta, Mario
Forniés Gracia, Juan
Fortuño Turmo, Consuelo
Fraile Dolado, José María
Franco Ontaneda, Santiago
Fuente del Rey, César de la
Fuente Leis, Germán de la
Gálvez Lafuente, José Antonio
García Clemente, Mª Pilar
García Landa, Berta
García Laureiro, José Ignacio
García Palacios, José Luis
García Ruíz, Joaquín
García Vinuesa, Luis Miguel
Garín Tercero, Javier
Burriel Lahoz, Ramón
Miguel Pardo, Mª Elisa de
Giménez Soro, Raquel
Gimeno Floría, Mª Concepción
Ibarra García, Ricardo
Jiménez Rupérez, Mª Victoria
Jiménez Sanz, Ana Isabel
Jiménez Villar, Josefina
Laguna Castrillo, Antonio
Laguna Castrillo, Mariano
Laguna Gómez, Mª Ángeles
Lahoz Díaz, Fernando José
Lamata Cristóbal, Mª Pilar
Larrea Arbáizar, Ángel
Larrodé Pellicer, Emilio
Lázaro Osoro, Francisco José
Lera García, Francisco
López Calvo, José Antonio
López de Lama, Ana Margarita
López Ram de Viú, Mª Pilar
Luis Vitalla, Fernando
Lydon, Donocadh Patrick
Marcos Martínez, Mercedes
Marquina García, Clara Isabel
Martín Casado, Marta
Martín Moreno, Luis
Martín Tello, Antonio Jesús
Martínez Buenaga, Francisco
Martínez Fernández, Elena
Martínez Martínez, Jesús Ignacio
Martínez Ovejas, Pedro
Mayoral Murillo, José Antonio
Mazo Torres, Juan José
Melero Estela, Julio
Menjón Ruíz, Babil
Merchán Álvarez, Francisco L.
Merino Filella, Pedro
Merino Rubio, Rosa Isabel
Millán Escolano, Ángel
Miravete de Marco, Antonio
Modrego Pérez, Francisco Javier
Mora Alfonso, Mario
Moral Gámiz, Agustín del
Morellón Alquézar, Luis
Morón Lafuente, Mª Carmen
Navarro Gómez, Fernando
Navarro Linares, Rafael
Navarro Martín, Rafael
Oliete Terraz, Patricia Beatríz
Oliván Escó, Montserrat
Omenat Val, Ana Carmen
Oñate Rodríguez, Enrique
Orduna Catalán, Jesús
Orera Clemente, Víctor Manuel
Oriol Langa, Luis
Oro Giral, Luis Antonio
Palacio Parada, Fernando
Palacios Latasa, Elías
Peña Torre, José Ignacio
Pérez Torrente, Jesús J.
Piñol Lacambra, Milagros
73
Pires Ezquerra, Elisabet
Proietti, Maria Grazia
Puértolas Ráfales, José Antonio
Rillo Millán, Conrado
Rojo Martínez, José Antonio
Romero Soria, Pilar
Ros Latienda, Blanca
Royo Cantabrana, Eva
Rubín Llera, Javier
Rueff, Jean Michel
Salvatella Ibáñez, Luis
Sánchez Sierra, Mª Concepción
Sanjuán Álvarez, Mª Luisa
Savirón Sánchez, María
Serrano Ostáriz, José Luis
Sicilia Martínez, Violeta
Sierra Travieso, Teresa
Sola Larraya, Eduardo
Sotelo Mieg, Andrés Emilio
Stankiewicz, Jolanta
Tahir, Rachid
Tejel Altarriba, Mª Cristina
Tejero López, Tomás
Teresa Nogueras, José Mª de
Tomás Lisbona, Milagros
Uriel Rubio, Santiago
Urriolabeitia Arrondo, Esteban Pablo
Usón Finkenzeller, Miguel Ángel
Viguri Rojo, Fernando
Villacampa Naverac, Belén
Villacampa Pérez, Mª Dolores
Villarroya Aparicio, Beatríz Eva
74
1.4.- Departamentos de Investigación
Research Departments
Ciencia y Tecnologías Químicas
Chemistry: Science and Technology
Química de los Compuestos Organometálicos
Organometallic Chemistry
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Ara Laplana, Irene V.
Casas del Pozo, José Mª
Falvello, Lawrence Rocco
Forniés Gracia, Juan
Fortuño Turmo, Consuelo
Gimeno Floría, Mª Concepción
Jiménez Villar, Josefina
Laguna Castrillo, Mariano
Laguna Castrillo, Antonio
Martín Tello, Antonio Jesús
Martínez Buenaga, Francisco
Menjón Ruiz, Babil
Navarro Martín, Rafael
Sicilia Martínez, Violeta
Tomás Lisbona, Milagros
Urriolabeitia Arrondo, Esteban
Usón Finkenzeller, Miguel A.
Villacampa Pérez, Mª Dolores
Prof. Titular
Prof. Titular
Prof. Asociado Permanente (Categoria Catedrático)
Catedrático
Prof. Titular Esc. Univ.
Investigador Científico
Prof. Titular Esc. Univ.
Prof. de Investigación
Catedrático
Científico Titular
Prof. Titular
Científico Titular
Catedrático
Prof. Titular Esc. Univ.
Investigador Científico
Científico Titular
Prof. Titular
Prof. Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Bielsa Sebio, Raquel
Cerrada Lamuela, Elena
Contel Fernández, María
Crespo Zaragoza, Olga
Chacuche, Naima
Diosdado Cabrera, Beatriz
Escorihuela Vitales, Inmaculada
García Monforte, María Ángeles
Jones, Lathe
Lardiés Miazza, Nora
Larraz Duaso, Carmen
Luquín Martínez, Mª Asunción
Martín Julián, Francisco
Sanz Calvo, Sergio
Soler García, Tatiana
Becario
Prof. Asociado
Investigador Contratado
Prof. Asociado
Becario
Becario
Becario
Becario
Becario
Becario
Becario
Becario
Becario
Becario
Becario
75
Química de la Coordinación y Catálisis Homogénea
Coordination Chemistry and Homogeneous Catalysis
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Carmona Gascón, Daniel
Ciriano López, Miguel Ángel
Elduque Palomo, Ana Isabel
Esteban Pérez, Montserrat
Esteruelas Rodrigo, Miguel A.
Ferrer Cerra, Joaquina
García Clemente, Mª Pilar
Jiménez Rupérez, Mª Victoria
Lahoz Díaz, Fernando José
Lamata Cristóbal, Mª Pilar
López Calvo, José Antonio
López de Lama, Ana Margarita
Modrego Pérez, Francisco J.
Oro Giral, Luis Antonio
Pérez Torrente, Jesús J.
Sola Larraya, Eduardo
Tejel Altarriba, Mª Cristina
Viguri Rojo, Fernando
Villarroya Aparicio, Beatríz Eva
Prof. de Investigación
Prof. de Investigación
Prof. Titular
Catedrática Esc. Univer.
Catedrático
Prof. Titular Esc. Univ.
Prof. Titular
Científico Titular
Investigador Científico
Prof. Titular Esc. Univ.
Prof. Titular
Prof. Titular Esc. Univ.
Prof. Titular
Catedrático
Prof. Titular
Científico Titular
Investigador Científico
Prof. Titular Esc. Univ.
Prof. Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Acosta Martínez, Ana
Asensio Fletas, Adriana
Barrio Sena, Mª Pilar
Bolaño García, Tamara
Buil Juan, Mª Luisa
Camerano Chirón, José A.
Casado Lacabra, Miguel Á.
Castarlenas Chela, Ricardo
Eguillor Armendáriz, Beatríz
Fabra Caro, María José
Fernández Álvarez, Frco. J.
García Camprubí, Alba
García Villalta, Néstor
González Marín, Ana Isabel
Hernández Rojas, Yohar
Jiménez Franco, Sonia
Martín Casado, Marta
Mateo Pérez, A. Concepción
Oliván Esco, Montserrat
Oñate Rodríguez, Enrique
Rodríguez Martínez, Ricardo
Royo Cantabrana, Eva
Tajada Serrano, Mª Ángeles
Tejero Artigas, Santiago
Todorova Dobrinovitch, Isabel
Torres Blasco, Olga
Becario
Becario
Becario
Becario
Contr. "Ramón y Cajal"
Becario
Contr. "Ramón y Cajal"
Contratado "I3P" Doctor
Becario
Becario
Investigador Contratado
Becario
Becario
Investigador Contratado
Becario
Becario
Contr. "Ramón y Cajal"
Becario
Contr. "Ramón y Cajal"
Prof. Asociado
Becario
Prof. Asociado
Investigador Contratado
Becario
Becario
Becario
● Personal Técnico / Technical personnel
−
−
Martín Albina, Mª Luisa
Plou Lafuente, Pablo
Contratado "I3P" Técnico
Técnico Superior
76
Química Orgánica
Organic Chemistry
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
−
−
−
−
−
−
Cativiela Marín, Carlos
Díaz de Villegas Soláns, Mª Dolores
Fraile Dolado, José María
Franco Ontaneda, Santiago
Gálvez Lafuente, José Antonio
García Laureiro, José Ignacio
López Ram de Viu, Mª Pilar
Mayoral Murillo, José Antonio
Merchán Alvarez, Francisco L.
Merino Filella, Pedro
Pires Ezquerra, Elisabet
Salvatella Ibáñez, Luis
Tejero López, Tomás
Catedrático
Investigador Científico
Científico Titular
Prof. Titular
Prof. Titular
Investigador Científico
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular Esc. Univ.
Prof. Titular
Prof. Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Aguirre Ardanaz, Daniel
Alias Niño, Miriam
Badorrey Miguel, Ramón Ángel
Ballano Ballano, Gema
Casabona Agudo, Diego
Díez Gracia, Roberto
Etayo Pérez, Pablo
Gil Ferrás, Ana
Herrerías Larripa, Clara
Jiménez Sanz, Ana Isabel
Lafuente Aranda, Gustavo
Lasa Ventura, Marta
Matés Valdivieso, Juan Antonio
Royo Gracia, Soledad
Solanas Díaz, Mª Concepción
Vanni, Mannucci
Villalba Bayo, Isabel
Becario
Prof. Asociado
Prof. Ayudante
Becario
Becario
Becario
Becario
Becario
Prof. Ayudante
Contr. “Ramón y Cajal”
Contratado
Becario
Becario
Becario
Becario
Becario
Investigador Contratado
77
Ciencia y Tecnología de Materiales
Materials Science and Technology
Espectroscopía de Sólidos
Spectroscopy of Solids
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
-
Alcalá Aranda, Rafael
Alonso Gascón, Pablo Javier
Cases Andreu, Rafael
Martínez Martínez, Jesús Ignacio
Merino Rubio, Rosa Isabel
Orera Clemente, Víctor Manuel
Sanjuán Álvarez, Mª Luisa
Villacampa Naverac, Belén
Catedrático
Prof. de Investigación
Prof. Titular
Prof. Titular
Científico Titular
Prof. de Investigación
Científico Titular
Prof. Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
Alonso Gutiérrez, Pablo
Laguna Bercero, Miguel Ángel
Rodríguez Martínez, F. Javier
Sánchez Somolinos, Carlos
Becario
Becario
Becario
Contratado "I3P" Doctor
● Personal técnico / Technical personnel
−
−
Gotor Montañés, Rubén
Laguna Gómez, María Ángeles
Técnico Contratado
Técnico Superior
78
Física del Estado Sólido a Bajas Temperaturas
Low Temperature Solid State Physics
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Artigas Alava, Miguel
Bartolomé Usieto, Fernando
Bartolomé Sanjoaquín, Juan
Blasco Carral, Javier
Burriel Lahoz, Ramón
Camón Lasheras, Agustín
Castro Corella, Miguel
Chaboy Nalda, Jesús
Fernández Novoa, Julio F.
García Ruíz, Joaquín
García Vinuesa, Luis Miguel
Proietti Cecconi, Mª Grazia
Luis Vitalla, Fernando
Morón Lafuente, Mª Carmen
Palacio Parada, Fernando
Palacios Latasa, Elías
Rillo Millán, Conrado
Rubín Llera, Javier
Prof. Titular
Científico Titular
Prof. de Investigación
Científico Titular
Prof. de Investigación
Científico Titular
Prof. Titular
Científico Titular
Científico Titular
Prof. de Investigación
Prof. Titular
Prof. Titular
Científico Titular
Científico Titular
Prof. de Investigación
Prof. Titular
Prof. de investigación
Prof. Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
−
−
−
−
−
−
−
Campo Ruiz, José Javier
Herrero Martín, Javier
Herrero Albillos, Julia
Laguna Marco, Mª Ángeles
López Ruiz, Román
Millán Escolano, Ángel
Piquer Oliet, Cristina
Plugaru, Neculai
Rodríguez Velamazán, José Alberto
Stankiewicz Ciepielewska, Jolanta
Subías Peruga, Gloria
Tocado Martínez, Leticia
Contr. "Ramón y Cajal"
Becario
Becario
Becario
Becario
Científico Titular (c.s.)
Cont. "Ramón y Cajal"
Investigador Contratado
Becario
Contr. "Ramón y Cajal"
Contr. "Ramón y Cajal"
Becario
● Personal técnico / Technical personnel
−
−
Gil Andaluz, Miguel Ángel
Sánchez Sierra, Mª Concepción
Técnico Contratado
Técnico Superior
79
Magnetismo de Sólidos
Magnetism of Solids
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
−
Algarabel Lafuente, Pedro A.
Arnaudas Pontaque, José Ignacio
Fuente del Rey, César de la
Ibarra García, M. Ricardo
Marquina García, Clara Isabel
Moral Gámiz, Agustín del
Morellón Alquézar, Luis
Teresa Nogueras, José María de
Prof. de Investigación
Prof. Titular
Prof. Titular
Catedrático
Científico Titular
Catedrático
Prof. Titular
Científico Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
−
Benito Ruiz, Luis Pablo
Ciria Remacha, Miguel
Mágen Domínguez, César
Serrate Donoso, David
Sikora, Marcin Andrzej
Zajac, Dariusz Andrzej
Becario
Contr. "Ramón y Cajal"
Becario
Becario
Contratado
Contratado
● Personal técnico / Technical personnel
−
Martín Sacristán, Carlos
Técnico Superior
80
Materiales de Interés Tecnológico
Technological Materials
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
−
−
−
−
Angurel Lambán, Luis Alberto
Díez Moñux, Juan Carlos
Fuente Leis, Germán de la
Larrea Arbáizar, Angel
Lázaro Osoro, Francisco José
Lera García, Francisco
Miravete de Marco, Antonio
Navarro Linares, Rafael
Peña Torre, José Ignacio
Puértolas Ráfales, José Antonio
Rojo Martínez, José Antonio
Prof. Titular
Prof. Titular
Investigador Científico
Científico Titular
Prof. Titular
Prof. Titular
Catedrático
Catedrático
Prof. Titular
Catedrático
Prof. Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Carrera Alegre, Marco Antonio
Caudevilla Portero, Hortensia
Cuartero Salafranca, Jesús
Francisco García, Isabel de
Gimeno Bellver, Fernando José
Guzmán de Villoria L., Roberto
Korrany Hassan, Mohamed
Lahoz Espinosa, Ruth
Lennikov, Vassili
López Gascón, Clara Isabel
Martínez Fernández, Elena
Mora Alfonso, Mario
Oliete Terraz, Patricia Beatriz
Ranz Angulo, David
Sotelo Mieg, Andrés Emilio
Vargas Silva, Gustavo Adolfo
Contratado
Prof. Asociado
Prof. Asociado
Becario
Becario
Becario
Becario
Contratado
Becario
Becario
Contratado ”I3P” Doctor
Prof. Asociado
Prof. Asociado
Becario
Prof. Asociado
Becario
● Personal técnico / Technical personnel
−
−
García Garcés, Miguel
Gómez García, José Antonio
Prof. Asociado
Contratado
81
Nuevos Materiales Orgánicos
New Organic Materials
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
−
−
−
−
−
−
Andreu Solano, Raquel
Barberá Gracia, Joaquín
Garín Tercero, Javier
Marcos Martínez, Mercedes
Navarro Gómez, Fernando
Omenat Val, Ana Carmen
Orduna Catalán, Jesús
Oriol Langa, Luis
Piñol Lacambra, Milagros
Ros Latienda, Blanca
Serrano Ostáriz, José Luis
Sierra Travieso, Teresa
Prof. Titular
Prof. Titular
Prof. Titular
Investigador Científico
Prof. Titular Esc. Univ.
Científico Titular
Científico Titular
Prof. Titular
Prof. Titular Esc. Univ.
Prof. Titular
Catedrático
Científico Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Carrasquer Lozano, Laura
Cavero Menéndez, Emma
Forcén Jiménez, María Patricia
Giménez Soro, Raquel
Gimeno Gomaz, Nélida
López Herranz, Carolina
Martín Rapún, Rafael
McKenna, Mark
Piñol Lacambra, Rafael
Puig Fernández, Laura
Silvino Chinelatto, Luiz
Tejedor Bielsa, Rosa
Uriel Rubio, Santiago
Viñuales Martínez, Ana Isabel
Becario
Becario
Becario
Prof. Ayudante
Becario
Becario
Becario
Becario
Becario
Becario
Becario
Prof. Asociado
Prof. Asociado
Becario
82
Teoría y Simulación de Sistemas Complejos
Theory and Simulation of Complex Systems
● Personal científico permanente / Scientific staff
−
−
−
−
−
−
Badía Majós, Antonio
Falo Forniés, Fernando
Floría Peralta, Mario
Martín Moreno, Luis
Martínez Ovejas, Pedro
Mazo Torres, Juan José
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular Esc. Univ.
Prof. Titular
● Personal científico contratado y becarios / Contract scientists and Ph.D. students
−
−
−
−
−
Cuesta López, Santiago
García Palacios, José Luis
Gómez Gardeñes, Jesús
López-Tejeira Sagüés, Fernando
Zueco Láinez, David
Becario
Contr. "Ramón y Cajal"
Becario
Contratado
Becario
83
1.5.- Unidades de Apoyo
Support Services
Administración y Gerencia
Secretary and Administrator
−
−
−
−
Arasanz Lanau, Mª Concepción
Elías Martínez, Mª Isabel
Marco Pérez, Concepción
Miguel Pardo, Mª Elisa de
Administrativo
Auxiliar Administrativo
Auxiliar Administrativo
Técnico de Gestión
Personal Técnico
Technical Personnel
● Servicios generales
Technical services
−
−
−
−
Estepa Millán, Luis Carlos
García Casanova, Rosa
Nieto Méndez, Yolanda
Romero Soria, Mª Pilar
Titulado Técnico Especializado
Titulado Técnico Especializado
Contratado "I3P" Técnico
Titulado Superior
● Apoyo a departamentos
Departmental support staff
−
−
−
−
−
Bernad Pérez, Ana Lidia
Francisco Tomás, Carmen de
Martínez Ruiz, Marisol
Mayoral Asensio, Isabel
Sauras Fernández, Francisco
Ayudante de Investigación
Ayudante de Investigación
Ayudante de Investigación
Titulado Técnico Especializado
Ayudante de Investigación
Servicios Generales
Technical Services
•
•
•
•
Oficina técnica / Technical office
Espectrometría de masas / Mass spectrometry
Resonancia magnética nuclear / Nuclear magnetic resonance
Análisis térmico / Thermal analysis
84
OFICINA TÉCNICA / TECHNICAL OFFICE
Diseño y fabricación de equipos científicos e infraestructura para la investigación
Design and fabrication of research equipment and infrastructure for research
Máquina de desgaste para UHPM
Conjunto óptico para división de haz láser
Wearing machine for UHPM
Optical bench for laser beam splitting
Palabras clave:
Infraestructura para investigación, diseño y
construcción de prototipos, modificación y
mejora
de
sistemas,
adquisición
de
equipamiento.
Keywords:
Research infrastructure, prototype design and
construction, systems improvement, new
equipment support.
Descripción:
Infraestructura general de laboratorios de
materiales. Hornos. Cámaras de tratamiento de
materiales. Sistemas de movimiento. Prensado
isostático y axial. Útiles para la investigación.
Adquisición de
láseres industriales y sus
sistemas
complementarios.
Apoyo
y
participación en los proyectos de carácter
técnico y aplicado del ICMA.
Persona de contacto:
Responsable del Servicio: Carlos Estepa
(cestepa@unizar.es).
Ubicación: Centro Politécnico Superior. Edificio
Torres Quevedo. María de Luna, 3. 50018
Zaragoza. Tel.: 976 762523.
Description:
General infrastructure for materials laboratories.
Furnaces. Materials processing chambers.
Translational systems. Isostatic and axial
presses. Research equipment. Support for
industrial laser and complementary systems
acquisitions. Support for technical projects at
ICMA.
Contact person:
Head Engineer: Carlos Estepa
(cestepa@unizar.es)
Address: Centro Politécnico Superior. Edificio
Torres Quevedo. María de Luna, 3. 50018
Zaragoza. Tel.: 976 762523.
85
ESPECTROMETRÍA DE MASAS / MASS SPECTROMETRY
Palabras clave:
Espectrometría de Masas.
Keywords:
Mass spectrometry.
Descripción del equipo:
Autoespec VG (Actualmente Waters)
Equipment:
VG Autospec (Waters).
Técnicas e instrumentación disponibles:
Analizador magnético trisector EBE, de alta
resolución.
Sistemas de Introducción directa de muestras y
cromatografía de gases.
Sistemas de Ionización: EI+ , CI+, CI-, FAB+,
FAB-.
Available techniques:
EBE trisector high resolution analyzer.
Autosampler and gas chromatography.
Ionization systems: EI+ , CI+, CI-, FAB+, FAB-.
Personas de contacto:
Jefe del Servicio: Dr. Mariano Laguna
(mlaguna@unizar.es).
Responsable del Servicio: Dr. Jesús Orduna
(jorduna@unizar.es).
Titulado Técnico: Rosa M. García
(mgarcas@unizar.es).
Contacts:
Head of the Service: Dr. Mariano Laguna
(mlaguna@unizar.es).
Scientist in charge: Dr. Jesús Orduna
(jorduna@unizar.es).
Technical personnel: Rosa M. García
(mgarcas@unizar.es).
Address: Facultad de Ciencias, Edificio A,
Pedro Cerbuna, 12. 50009 Zaragoza. Tel.: 976
761181/1194/3313.
Ubicación: Facultad de Ciencias, Edificio A,
Pedro Cerbuna, 12. 50009 Zaragoza. Tel.: 976
761181/1194/3313).
86
ESPECTROSCOPIA DE RESONANCIA MAGNÉTICA NUCLEAR
NUCLEAR MAGNETIC RESONANCE
Palabras clave: RMN
Keywords: NMR
Descripción:
La configuración de los equipos está enfocada
principalmente a la resolución de problemas de
determinación estructural y estudio de procesos
dinámicos, todo ello en solución. No obstante,
se dispone de un accesorio de sólidos que
permite abordar estudios de CPMAS. Los
usuarios pueden acceder a las prestaciones del
Servicio en dos modos de utilización distintos
pero complementarios entre sí: en autoservicio o
realización de experimentos por parte del
personal del Servicio.
Equipment:
The configuration of the equipment is directed to
the resolution of structural problems and the
study of dynamic processes in solution. In
addition, CPMASS studies can be carried out
using the solid-state accessory. Users can
acquire data by themselves or through the
services of the staff technicians.
Técnicas e instrumentación disponibles:
En la actualidad el servicio dispone de un total
de cuatro instrumentos de RMN:
o 2 AVANCE-400.
o Bruker: ARX-300
o Varian: Unity 300
Se dispone de sondas de detección directa
(BBO) e inversa (BBI), controlador para la
realización de experimentos a temperatura
variable entre -130 ºC y 200 ºC, cambiador
automático de muestras utilizado para la
adquisición de espectros de 1H ,13C, 31P y 19F.
Personas de contacto: Jefe del Servicio: Dr.
Esteban Urriolabeitia (esteban@unizar.es).
Responsable del Servicio: Dra. Pilar Romero
(promero@unizar.es).
Técnico contratada: Yolanda Nieto
(nieto@unizar.es)
Ubicación: Facultad de Ciencias, Edificio A,
Pedro Cerbuna, 12. 50009 Zaragoza. Tel.: 976
762532/2778.
Available techniques:
Four NMR instruments are available:
o 2 AVANCE-400.
o Bruker: ARX-300
o Varian: Unity 300
Direct detection probes (BBO) and inverse
detection probes (BBI) are currently used. A
variable temperature accessory (-130 to 200 ºC.)
is also available. An autosampler is used for
1
13
31
19
acquisition of H , C, P, and F spectra.
Contact persons:
Head of the Service: Dr. Esteban Urriolabeitia
(esteban@unizar.es).
Scientist in charge: Dra. Pilar Romero
(promero@unizar.es).
Technical personnel: Yolanda Nieto
(nieto@unizar.es).
Address: Facultad de Ciencias, Edificio A,
Pedro Cerbuna, 12. 50009 Zaragoza. Tel.: 976
762532/2778.
87
ANÁLISIS TÉRMICO DIFERENCIAL / DIFFERENTIAL THERMAL ANALYSIS
Palabras clave:
Análisis
térmico
termogravimetría.
diferencial,
calorimetría,
Keywords:
Differential thermal
thermogravimetry.
analysis,
calorimetry,
Descripción del equipo:
Calorímetros diferenciales de barrido PerkinElmer DSC-7 y Thermal Análisis TA2910.
Termobalanza TA2960.
Equipment:
Differential scanning calorimeters Perkin-Elmer
DSC-7 and Thermal Analysis TA2910.
Thermobalance TA2960.
Técnicas y/o instrumentación disponibles:
Calorimetría diferencial de barrido (DSC) desde
120 K hasta 1000 K. Termogravimetría (TG)
desde 300 K hasta 1500 K. Masa de muestra
entre 5 mg y 100 mg.
Available techniques:
Differential scanning calorimetry (DSC) from 120
K to 1000 K. Thermogravimetry (TG) from 300 K
to 1500 K. Sample mass between 5 mg and 100
mg.
Personas de contacto:
Prof. José Luis Serrano (joseluis@unizar.es).
Prof. Ramón Burriel (burriel@unizar.es).
Contacts:
Prof. José Luis Serrano (joseluis@unizar.es).
Prof. Ramón Burriel (burriel@unizar.es).
Ubicación: Facultad de Ciencias, Edificio D,
Pedro Cerbuna, 12. 50009 Zaragoza. Tel.: 976
761209/1223.
Address: Facultad de Ciencias, Edificio D,
Pedro Cerbuna, 12. 50009 Zaragoza. Tel.: 976
761209/12.
88
2.- Actividades
Activities
89
90
2.1.- Líneas de Investigación
Research Areas
91
2.1.1.- Ciencia y Tecnologías Químicas
Chemistry: Science and Technology
93
Arquitectura
molecular
organometálicos.
con
compuestos
El desarrollo de los métodos sintéticos nos permite
conocer las posibilidades de preparación de
compuestos de magnitud molecular controlada
mediante el uso de diversas estrategias:
1) Empleo de ligandos polifuncionales con varios
átomos dadores que permitan la polimerización. El
grupo emplea entre otros: sacarinatos, cianuratos,
alquiniluros, cianuros, alquinotiolatos, fosfinoalquinos,
ligandos "pincer", ditiolatos, fosfino- y aminocarboranos y sus derivados, ferrocenil-derivados,
ditiolenos, fosfuros e iluros.
2) Incremento de la magnitud molecular del
compuesto por interacciones metal-metal solas o
favorecidas por ligandos puente. En este apartado se
explotan metalofilias e interacciones dador-aceptor
entre centros metálicos de configuración de capa
completa en las que el grupo ha sido pionero tanto en
su descubrimiento como en su desarrollo.
3) Arquitectura molecular mediante empleo de
interacciones débiles, preferentemente puentes de
hidrógeno. La utilización de este tipo de interacciones
no covalentes en química supramolecular es una
zona del máximo interés y permite llevar a cabo la
construcción de moléculas de gran tamaño en donde
las interacciones débiles permiten la transferencia de
determinado tipo de propiedades.
4) Desarrollo de "tectones" útiles en procesos de
autorreconocimiento y capaces por sí solos o con
ayuda de otras especies, de participar en procesos
de crecimiento de la molécula en una, dos o tres
dimensiones.
Organometallic molecular architecture
Developments in synthetic methodology have opened
new routes for controlling molecular size and shape
through diverse preparative strategies:
1) The use of polyfunctional ligands, entities with
numerous functional groups susceptible to controlled
ligand
reactivity
leading,
for
example,
to
polymerization. Among the polyfunctional ligands
currently in use are saccharinate, cyanurate,
alkynylylides,
cyanides,
alkynylthiolates,
phosphinoalkynes,
pincer
ligands,
dithiolates,
phosphinoand
aminocarboranes,
ferrocenyl
derivatives, dithiolenes, phosphides, and ylides.
2) Molecular size enhancement through metal-metal
interactions, both unsupported and bridged. This line
of work also employs metallophiles and donoracceptor interactions between closed-shell metal
centers, areas in which this members of this group
made pioneering discoveries and have led continued
development.
3)
Supermolecular
architecture
using
weak
interactions, principally hydrogen bonds. The use of
non-covalent contacts in supramolecular chemistry is
currently an area of increasing interest and activity,
because of the possibilities that exist for creating
aggregates in which intermolecular interactions permit
communication of magnetic and/or electronic
properties.
4) Development of tectons, which are useful in selfrecognition processes and able to participate in
recognition-based growth of aggregate structures in
one, two, or three dimensions.
Publicaciones:
J. P. H. Charmant, J. Forniés, J. Gómez, E. Lalinde, R. I. Merino, M. T. Moreno, A. G. Orpen. Synthesis and
Electrical and Optical Propierties of [PtTl2-xLix(C6F5)2(C≡CPh)2] (x = 0, 1). Organometallics 2003, 22, 652-656.
D. Abizanda, O. Crespo, M. C. Gimeno, J. Jiménez, A. Laguna. Synthesis and structure of new carborane-substituted
cyclotriphosphazenes. Chem. Eur. J. 2003, 9, 3510-3519.
P. Alvarez, E. Lastra, J. Gimeno, M. Bassetti, L. R. Falvello. Formation of a Cyclobutanediyl Ring: Intramolecular
[2+2] Cycloaddition of Allyl and Vinylidene C=C Bonds under Mild Conditions. J. Am. Chem. Soc. 2003, 125, 23862387.
Proyectos:
Complejos de oro y plata. Preparación, estructura y potenciales aplicaciones (BQU2001-2409-C02-01).
Compuestos organometálicos de metales de transición. Aproximaciones sintéticas a especies de interés científico
por su novedad estructural o de enlace o por sus propiedades (BQU2002-3997-C02-01).
Síntesis, caracterización y reactividad de complejos de paladio y platino con fosfoiluros y ligandos relacionados.
Procesos de activación C-H, C-P y C-C (BQU2002-00510).
Diseño, síntesis y estudio de compuestos de coordianción con ligandos polifuncionales; Cristalografía estructural no
rutinaria; Informática cristalográfica (BQU2002-00554).
Miembros del ICMA que participan en esta línea:
J. Forniés, A. Laguna, L. R. Falvello, M. Laguna, R. Navarro, M. Tomás, M. C. Gimeno, F. Martínez, M. A. Usón, M.
D. Villacampa, B. Menjón, J. M. Casas, I. Ara, E. Urriolabeitia, A. Martín, C. Fortuño, M. V. Sicilia, J. Jiménez, M.
Contel, O. Crespo, E. Cerrada, N. Chaouche, B. E. Diosdado, I. Escorihuela, M. A. García, C. Larraz, L. Jones, L. F.
Martín, M. T. Soler.
95
Aproximaciones sintéticas y determinación
estructural de compuestos de metales de
transición con propiedades de interés.
Synthetic
approaches
to,
and
structural
properties of, transition metal complexes with
novel properties
Uso de técnicas novedosas tales como la
electrocristalización, la electropolimerización, la
cristalización progresiva y otros métodos sintéticos
avanzados para preparar y aislar compuestos no
favorecidos en la síntesis tradicional. De esta
manera, se pretende obtener materiales moleculares,
compuestos bioinorgánicos, y otras sustancias con
propiedades de interés. Entre los compuestos
estudiados en esta línea figuran, entre otros, agentes
anti-tumorales,
materiales
moleculares
cuyas
moléculas fundamentales cambian de forma en
estado sólido y polímeros novedosos. Como ejemplo
de las técnicas novedosas empleadas en esta línea
sirve la electrocristalización que usa corriente
eléctrica para producir la cristalización de moléculas
con grupos laterales polimerizables.
Esta línea incluye la determinación estructural de los
nuevos compuestos sintetizados, utilizando las
técnicas necesarias, sean rutinarias o no, difracción
de monocristal u otras técnicas. Esta linea engloba el
amplio esfuerzo de este grupo en el desarrollo y uso
de técnicas neutrónicas. Este grupo está involucrado
en la ampliación de un difractómetro de neutrones de
monocristal (Argonne National Laboratory) y en el
Equipo de Diseño de un nuevo difractómetro (SNS Oak Ridge National Laboratory) que permitirá el
análisis por difracción de neutrones, empleando
muestras pequeñas, lo cual abrirá nuevos horizontes
en el uso de neutrones en la química organometálica.
This line of investigation involves the development
and use of novel techniques -electrocrystallization,
electropolymerization, progressive crystallization- and
other advanced synthetic methods.
The target
products include molecular materials, bioinorganic
complexes, and other substances with potentially
useful properties.
Products obtained to date include a potential antitumor agent and a molecular material whose
component molecule changes shape dynamically,
reversibly, and non-destructively in the crystalline
state. Among the techniques used to prepare new
products is the electrocrystallization of molecules with
polymerizable side chains.
This line of research also encompasses structure
determination of the new products, whether by routine
or non-routine techniques involving single-crystal
diffraction or another appropriate technique. This line
also involves substantial effort in neutron techniques.
One member of this department is involved in
instrument improvement at Argonne National
Laboratory and is a member of the Instrument
Development Team for the Single Crystal
Diffractometer at the Spallation Neutron Source
(SNS) being built at Oak Ridge National Laboratory.
It is expected that the new instrument at SNS will
permit the use of smaller samples than presently
needed for neutron analysis, thus opening new
horizons for the use of neutron diffraction in inorganic
chemistry.
Publicaciones:
E. Alonso, J. Forniés, C. Fortuño, A. Martín, A. G. Orpen. Synthesis of Neutral and Anionic Tetranuclear Clusters
2
3
2
3
2
3
2
3
[Pt4(µ -PPh2)3{µ -PPh(1,2-η -Ph)-η P}(C6F5)4L] and [NBu4][(µ -PPh2)3{µ -PPh(1,2-η -Ph)-η P}(C6F5)5] Containing
Five Coordinate P Atoms and two Pt-Pt Bonds. Organometallics 2003, 22, 2723-2728.
E. J. Fernández, J. M. López-de-Luzuriaga, M. Monge, M. E. Olmos. J. Pérez, A. Laguna, A. A. Mohamed, J. P.
Fackler. {Tl[Au(C6Cl5)2]}n: A Vapochromic Complex. J. Am. Chem. Soc. 2003, 125, 2022-2023.
I. Ara, J. Forniés, M. A. García-Monforte, B. Menjón, R. M. Sanz-Carrillo, M. Tomás, A. C. Tsipis. Synthesis and
Characterisation of New Five-Coordinated Platinum Nitrosyl Derivatives: Density Functional Theory Study of Their
Electronic Structure. Chem. Eur. J. 2003, 9, 4094-4105.
I. P. Aleksandrova, J. Bartolomé, L. R. Falvello, J. M. Torres, A. A. Sukhovskii. Effect of Impurities on the Successive
Phase Transitions in (Cs1-xRbx)2ZnI4 Compounds. J. Phys. Condens. Matt. 2002, 14, 13623-13634.
Proyectos:
Complejos de oro y plata. Preparación, estructura y potenciales aplicaciones (BQU2001-2409-C02-01).
Compuestos organometálicos de metales de transición. Aproximaciones sintéticas a especies de interés científico
por su novedad estructural o de enlace o por sus propiedades (BQU2002-3997-C02-01).
Síntesis, caracterización y reactividad de complejos de paladio y platino con fosfoiluros y ligandos relacionados.
Procesos de activación C-H, C-Py C-C (BQU2002-00510).
Diseño, síntesis y estudio de compuestos de coordianción con ligandos polifuncionales; Cristalografía estructural no
rutinaria; Informática cristalográfica (BQU2002-00554).
Miembros del ICMA que participan en esta línea:
J. Forniés, A. Laguna, L. R. Falvello, M. Laguna, M. Tomás, M. C. Gimeno, F. Martínez, M. A. Usón, M. D.
Villacampa, B. Menjón, J. M. Casas, I. Ara, A. Martín, C. Fortuño, M. V. Sicilia, J. Jiménez, M. Contel, O. Crespo, E.
Cerrada, N. Chaouche, B. E. Diosdado, N. Lardiés, L. Jones, M. A. Luquín.
96
Propiedades ópticas, eléctricas y magnéticas a
través de procesos de autorreconocimiento
Developing electronic, optical, and magnetic
properties through self-recognition
Estamos interesados en la preparación de nuevos
compuestos homo- y heteropolinucleares que
presenten propiedades ópticas, eléctricas o
magnéticas de interés. Para ello estamos utilizando
diferentes métodos sintéticos, entre los que destacan
las reacciones entre complejos o fragmentos con
comportamiento ácido de Lewis con otros de
comportamiento básico. Esta aproximación nos está
permitiendo obtener, por ejemplo, un importante
número y variedad de complejos polinucleares con
enlaces, u otro tipo de interacciones débiles, entre
diferentes centros metálicos o con puentes de
hidrógeno. Algunos de los compuestos preparados
presentan propiedades luminiscentes y es posible
modificar la frecuencia de emisión al variar el entorno
de coordinación o la distancia entre los centros
metálicos. Otros derivados, por ejemplo, los
obtenidos por interacción entre dadores y aceptores
de densidad electrónica o los que contienen cadenas
de centros metálicos, presentan interesantes
propiedades semiconductoras y de óptica no lineal.
Estamos estudiando también las interacciones
magnéticas que se presentan a través de
interacciones intermoleculares débiles.
We are interested in preparing new homo- or
heteropolynuclear compounds with useful electronic,
optical, or magnetic properties. To this end we are
employing diverse synthetic processes, such as Lewis
acid-base reactions between different complexes or
molecular fragments. Our approach has led to the
obtention of a growing number and variety of
polynuclear complexes with metal-metal bonds, with
weak inter-metal interactions, or with hydrogen bonds.
Some of the compounds obtained so far are
luminescent, and the emission frequency can be
modified by varying the coordination environment of
the metal or the metal-metal distance.
Other
products, some formed by interaction of electron
donors and acceptors and others which contain
chains of metal atoms, display non-linear optical and
semiconductor properties. In this line of research we
are also studying magnetic interactions mediated by
weak intermolecular contacts.
Publicaciones:
M. Bardají, P. Uznanski, C. Amiens, B. Chaudret, A. Laguna. Aurophilic complexes as gold atom sources in organic
media. Chem. Commun. 2002, 598-599.
E. Alonso, J. Forniés, C. Fortuño, A. Martín. A. G. Orpen. Reactivity of [NBu4][(C6F5)2M(µ-PPh2)2M'(acac-O,O')] (M,
M' = Pt, Pd) towards silver centers. Synthesis of polynuclear complexes containing M-Ag bonds (M = Pd, Pt).
Organometallics 2003, 22, 5011-5019.
M. Bardají, A. Laguna, M. R. Pérez, P.G. Jones. Unexpected ring-opening reaction to a new cyanamide-thiolate
ligand stabilized as a dinuclear gold complex. Organometallics 2002, 21, 1877-1881.
L. R. Falvello, E. M. Miqueleiz, M. Tomás. Effect of Supramolecular Aggregation on Coordination in Cobalt (II)
Complexes of 2-Imidazolidone. Indian J. Chem. A 2003, 42A, 2307-2315.
Proyectos:
Complejos de oro y plata. Preparación, estructura y potenciales aplicaciones (BQU2001-2409-C02-01).
Compuestos organometálicos de metales de transición. Aproximaciones sintéticas a especies de interés científico
por su novedad estructural o de enlace o por sus propiedades (BQU2002-3997-C02-01).
Síntesis, caracterización y reactividad de complejos de paladio y platino con fosfoiluros y ligandos relacionados.
Procesos de activación C-H, C-Py C-C (BQU2002-00510).
Diseño, síntesis y estudio de compuestos de coordianción con ligandos polifuncionales; Cristalografía estructural no
rutinaria; Informática cristalográfica (BQU2002-00554).
Miembros del ICMA que participan en esta línea:
J. Forniés, A. Laguna, L. R. Falvello, M. Laguna, R. Navarro, M. Tomás, M. C. Gimeno, F. Martínez, M. A. Usón, M.
D. Villacampa, B. Menjón, J. M. Casas, I. Ara, E. Urriolabeitia, A. Martín, C. Fortuño, M. V. Sicilia, J. Jiménez, M.
Contel, O. Crespo, E. Cerrada, I. Escorihuela, M. A. García, C. Larraz, L. Jones, L. F. Martín, M. T. Soler.
97
Procesos estequiométricos y catalíticos de
formación de enlaces carbono-carbono y
carbono-heteroátomo
por
mediación
de
compuestos de coordinación.
Comprende el estudio de reacciones de formación de
enlaces C-X, donde X puede ser un átomo de
carbono u otro elemento como oxígeno o nitrógeno,
realizadas por la presencia de compuestos de
coordinación.
Comprende
tanto
procesos
estequiométricos, esto es, reacciones que se realizan
de esta determinada manera por el papel que juega
el metal de transición coordinado o no con los
reactivos, como procesos en los que los compuestos
de coordinación actúan de catalizadores para una
síntesis orgánica dirigida tanto en procesos
homogéneos como heterogéneos. Para este fin se
utilizan compuestos de paladio(II), platino(II), oro(l) y
oro(llI) y los procesos a estudiar son reacciones de
acoplamiento C-C del tipo de Heck, Suzuki o Stille,
así como reacciones de hidratación e hidroaminación
de alquinos. Se presta especial atención al estudio de
los mecanismos por los que evolucionan, y al
aislamiento de posibles intermedios de reacción;
estamos extendiendo estos estudios a determinados
procesos de síntesis asimétrica.
Stoichiometric and catalytic carbon-carbon and
carbon-heteroatom bond formation reactions
mediated by coordination complexes
This line of research consists of the study of C-X bond
formation reactions, in which X can be carbon or
another element such as oxygen or nitrogen, in the
presence of coordination compounds. Included are
stoichiometric processes -- reactions in which the
transition metal plays a role in determining the
reaction pathway, whether or not the reactants are
bonded to the metal -- as well as specific organic
reactions in which coordination compounds act as
homogeneous
or
heterogeneous
catalysts.
Compounds of palladium(II), platinum(II), gold(I), and
gold(III) are used in studies of C-C coupling reactions
(Heck-, Suzuki-, or Stille-type), as well as in studies of
alkyne hydration or hydroamination reactions.
Special emphasis is given to the study of the reaction
mechanisms and the isolation of possible reaction
intermediates. This line of research is presently being
expanded to encompass the study of selected
asymmetric syntheses.
Publicaciones
L. R. Falvello, M. E. Margalejo, R. Navarro, R. Llusar, E. P. Urriolabeitia. Stabilized bis-ylides as a source of Carbene
ligands in Palladium(II) and Platinum(II) complexes. Organometallics 2003, 22, 1132-1144.
C. Gracia, G. Marco, R. Navarro, P. Romero, T. Soler, E. P. Urriolabeitia. C-P and C-H bond activaions and C-C
coupling in Bis-Phosphonium salts induced by Pt(II) complexes. Organometallics 2003, 22, 4910-4921.
P. Merino, T. Tejero, M. Laguna, E. Cerrada, A. Moreno, J. A. Lopez. An investigation of the 1,3-dipolar cycloaddition
reactions of N-benzyl-C-(2-pyridyl) nitrone. Direct entry to isoxazolidinyl C-nucleosides. Org. Biomol. Chem. 2003, 1,
2336-2342.
M. Contel, C. Izuel, M. Laguna, P. R. Villuendas, P. J. Alonso, R. H. Fish. Fluorous biphasic catalysis: Synthesis and
characterization of Copper(I) and Copper(II) fluoroponytailed 1,4,7-Rf-TACN and 2,2’-Rf-Bipyridine complexes, and
demonstration of their catalytic activity in the oxidation of hydrocarbons, olefins, and alcohols, including mechanistic
implications. Chem. Eur. J. 2003, 9, 4168-4178.
R. Casado, M. Contel, M. Laguna, M. P. Romero, S. Sanz. Organometallic Gold(III) compounds as catalysts for the
addition of water and methanol to terminal alkynes. J. Am. Chem. Soc. 2003, 125, 11925-11935.
Proyectos:
Síntesis, caracterización y reactividad de complejos de paladio y platino con fosfoiluros y ligandos relacionados.
Procesos de activación C-H, C-P y C-C (BQU2002-00510).
Miembros del ICMA que participan en esta línea:
M. Laguna, R. Navarro, M. E. Urriolabeitia, M. Contel, E. Cerrada, N. Lardiés, L. Jones, M. A. Luquín.
98
Diseño y síntesis de catalizadores. Estudios
mecanísticos.
Catalysis design and synthesis. Mechanistic
studies.
La investigación en esta línea persigue la concepción
y síntesis de nuevos complejos de metales de
transición con características adecuadas para actuar
como catalizadores homogéneos. Este tipo de
complejos
son,
por
lo
general,
especies
coordinativamente insaturadas o lábiles, esto es, que
poseen o pueden generar con facilidad vacantes de
coordinación, y contienen ligandos que les confieren
adecuadas prestaciones electrónicas, estéricas o de
estabilidad. Los nuevos complejos son sometidos a
estudios sistemáticos sobre su comportamiento en
disolución y su reactividad frente a pequeñas
moléculas y sustratos generalmente involucrados en
transformaciones catalíticas, con atención preferente
sobre los aspectos mecanísticos que puedan
repercutir en la cinética o la selectividad de las
transformaciones. Esta información permite identificar
las aplicaciones catalíticas idóneas de estos
complejos o diseñar nuevos procesos catalíticos.
Estas aplicaciones y procesos se someten a una
caracterización mecanística que proporcione las
claves para la optimización de los procesos y el rediseño de catalizadores más activos y selectivos.
La metodología de esta línea está basada
fundamentalmente en el uso de técnicas sintéticas y
espectroscópicas, estas últimas fundamentalmente
encaminadas a la realización de estudios cinéticos y
la detección de especies reactivas e intermedios
catalíticos.
This research line is aimed at the design and
synthesis of new transition metal complexes with
potential application as homogeneous catalysts. In
general, these compounds are unsaturated or labile
species, therefore featuring coordination vacancies or
a facile access to them, and contain ancillary ligands
conferring adequate electronic, steric or stability
properties. The solution behavior of the compounds
and their reactivity towards small molecules and
substrates
commonly
involved
in
catalytic
transformations are systematically investigated, with
emphasis on those mechanistic aspects likely to
affect the rate and selectivity of the reactions. This
information allows to recognize successful catalytic
applications of the new complexes and can enlighten
the development of new processes. Such applications
and processes are subjected to a mechanistic
characterization providing key information for process
optimization and catalyst re-design.
This line uses a research methodology based on
synthetic and spectroscopic techniques, the latter
being mainly focused on kinetic studies and the
detection of reactive species and catalytic
intermediates.
Publicaciones:
M. Martín, E. Sola, O. Torres, P. Plou, L. A. Oro. Versatility of cyclooctadiene ligands in Iridium chemistry and
catalysis. Organometallics 2003, 22, 5406-5417.
M. V. Jiménez, E. Sola, J. Caballero, F. J. Lahoz, L. A. Oro. Alkene C-H activations at dinuclear complexes
promoted by oxidation. Angew. Chem. Int. Ed. 2002, 41, 1208-1211.
Y. Yuan, M. V. Jiménez, E. Sola, F. J. Lahoz, L. A. Oro. Sequential C-H activation and dinuclear insertion of ethylene
promoted by a Diiridium complex. J. Am. Chem. Soc. 2002, 124, 752-753.
Proyectos:
Desarrollo de aplicaciones catalíticas homogéneas promovidas por complejos de metales de transición (BQU200305412-C02-01).
Desarrollo de aplicaciones catalíticas homogéneas promovidas por complejos de metales de transición (BQU200305412-C02-02).
Catálisis homogénea por complejos organometálicos de metales de transición (BQU2000-1170).
Integral training and research in homogeneous catalysis by organometallic compounds (HPMT-CT-2000-00200).
Miembros del ICMA que participan en esta línea:
L. A. Oro, E. Sola, J. J. Pérez-Torrente, V. Jiménez, J. A. López, F. J. Lahoz, A. I. Elduque, M. Martín, J. Navarrro, A.
Acosta, S. Tejero, O. Torres, P. Plou.
99
Complejos polinucleares homo y heterometalicos.
Homo and heterometallic polynuclear complexes.
Los compuestos polimetálicos, que incluyen a los
complejos dinucleares, polinucleares y clusters,
gozan de una posición intermedia entre los complejos
mononucleares y las superficies metálicas. La
presencia de, al menos, dos átomos metálicos en una
misma molécula permite la interacción de sustratos
orgánicos con un centro metálico (single site) en
presencia de otro próximo, que puede reactivarlo, o
simultáneamente con dos o varios centros metálicos
(multisite) facilitando la activación y transformación
del sustrato en productos. En esta dirección,
estudiamos la reactividad asociada a más de un
centro metálico buscando actuaciones sinérgicas de
los metales y preparamos clusters metálicos como
modelos moleculares de superficies metálicas.
Alternativamente,
se
sintetizan
dendrímeros
funcionalizados en la superficie que pueden actuar
como soportes para la incorporación de metales
activos en reacciones catalíticas, que son fácilmente
separables de los productos de reacción. Una
dirección relevante en la síntesis de complejos
polinucleares es nuestra orientación hacia la
preparación de compuestos con una determinada
estructura. En particular, estamos interesados en la
preparación
de
oligómeros
metálicos
unidimensionales y cadenas metálicas (“metal-wires”)
mediante la formación de enlaces metal-metal,
susceptibles de presentar propiedades conductoras.
The polymetallic compounds, including dinuclear,
polynuclear complexes and metal clusters, benefit an
intermediate position between the mononuclear
complexes and the metal surfaces. The presence of
two metal atoms in a molecule allows the interaction
of organic substrates with either a metal centre (single
site) in the nearby of another close metal, which can
reactivate it, or with two or more metal centres
(multisite). In this way the activation and
transformation of the substrate into products can be
facilitated. With this aim, we are studying the reactivity
associated to more than one metal centre looking for
a synergism of the metals, and we prepare metal
clusters as molecular models of metallic surfaces.
Alternatively,
we
are
synthesising
surfacefunctionalized dendrimers to act as soluble supports
for complex metal fragments active in catalytic
reactions, which can be easily separated from the
products. A relevant direction in the syntheses of
polynuclear complexes is our orientation to prepare
compounds with special structures. In particular, we
are interested in the preparation of 1D metal
oligomers and metal chains (metal wires) through the
formation of metal-metal bonds, which could show
electrical conductivity.
Publicaciones:
C. Tejel, M. A. Ciriano, M. Bordonaba, J. A. López, F. J. Lahoz, L. A. Oro. Structural and dynamic studies on amido
bridged Rhodium and Iridium complexes. Chem. Eur. J. 2002, 8, 3128-3138.
C. Tejel, M. A. Ciriano, B. E. Villarroya, J. A. López, F. J. Lahoz, L. A. Oro. A hexanuclear Iridium chain. Angew.
Chem. Int. Ed. 2003, 42, 529-532.
M. A. Casado, J. J. Pérez-Torrente, M. A. Ciriano, I. T. Dobrinovitch, F. J. Lahoz, L. A. Oro. Stereoselective oxidativeadditions of iodoalkanes and activated alkynes to a sulfido-bridged heterotrinuclear early-late (TiIr2) complex. Inorg.
Chem. 2003, 42, 3956-3964.
Proyectos:
Nuevos clusters y cadenas metálicas basadas en rodio e iridio y reactividad binuclear (PB98-0641).
Síntesis, estructura y reactividad de complejos mono- y poli-metálicos con posibles aplicaciones catalíticas o
conductoras (BQU2002-0074).
Miembros del ICMA que participan en esta línea:
M. A. Ciriano, C. Tejel, B. E. Villarroya, M. A. Casado, J. A. Camerano, S. Jiménez.
100
Catalizadores organometálicos enantioselectivos.
Organometallic enantioselective catalysts.
Muchos de los constituyentes de los seres vivos son
ópticamente activos. En consecuencia, los receptores
biológicos habitualmente diferencian entre los dos
enantiómeros de una molécula con actividad
biológica. Esta característica hace que la demanda
de compuestos quirales con elevada pureza
enantiomérica
esté
creciendo
de
manera
espectacular durante los últimos años.
La forma más eficaz, sin ninguna duda, de llevar a
cabo las síntesis de productos enantioselectivamente
es la catálisis. Mediante el empleo de un auxiliar
quiral, con una sola molécula de un catalizador se
puede obtener un número elevado de moléculas del
producto quiral deseado.
En la línea de investigación “Catalizadores
Organometálicos Enantioselectivos” se aborda la
preparación de compuestos organometálicos quirales
de metales del grupo del platino y el estudio de su
actividad como catalizadores en procesos catalíticos
en fase homogénea de transferencia de hidrógeno,
Diels-Alder, adiciones de Michael y cicloadiciones
1,3-dipolares de alquenos a nitronas.
Como objetivo principal figura el estudio de los ciclos
catalíticos implicados. Para ello, se intenta detectar y
caracterizar los intermedios organometálicos que
participan en los mismos. Su caracterización permite
proponer los caminos de reacción que operan,
optimizar los sistemas catalíticos y proponer el origen
de la selectividad, en particular la enantioselectividad,
de los mismos.
Most of the constituents of live beings are optically
active. Thus, the biological receptors usually
distinguish between the two enantiomers of a
biologically active molecule. This fact causes that the
industrial demand of chiral compounds with high
enantiomeric purity is growing in a spectacular way
during the last years.
The most efficient way, without any doubt, to carry out
the enantioselective synthesis of products is
Catalysis. Using a chiral auxiliary, just with only one
catalyst molecule, it is possible to obtain a great
number of molecules of the needed chiral compound.
In the research line “Organometallic Enantioselective
Catalysts” we attempt the preparation of quiral
organometallic compounds based on platinum group
metals and the study of their catalytic activity in
homogeneous processes such as hydrogen transfer
reactions, Diels-Alder, Michael additions and 1,3dipolar cycloadditions of alkenes to nitrones.
The main objective is the study of the catalytic cycles
attempting the detection and characterisation of the
involved organometallic intermediates. From their
characterisation it is possible to propose the catalytic
reaction paths, to optimise the catalytic systems, to
explain the observed selectivities and to propose the
origin of the enantioselectivity.
Publicaciones:
D. Carmona, F. J. Lahoz, S. Elipe, L. A. Oro, M. P. Lamata, F. Viguri, F. Sánchez, S. Martínez, C. Cativiela, M. P.
López Ram-de-Víu. Synthesis, characterization, properties, and asymmetric catalytic Diels-Alder of chiral-at-metal
phosphinooxazoline-Rhodium(III) and-Iridium(III) complexes. Organometallics 2002, 21, 5100-5114.
D. Carmona, M. P. Lamata, F. Viguri, I. T. Dobrinovich, F. J. Lahoz, L. A. Oro. On the sense of the enantioselection in
hydrogen transfer reactions from 2-propanol to ketones. Adv. Synth. Catal. 2002, 344, 499-502.
D. Carmona, M. P. Lamata, L. A. Oro. Half-sandwich complexes with chiral ligands and their use as enantioselective
catalysts. Eur. J. Inorg. Chem. 2002, 2239-2251.
Proyectos:
Síntesis y caracterización de organocomplejos quirales en el metal: aplicaciones en catálisis enantioselectiva (BQU2000-0907).
Catálisis enantioselectiva por compuestos organometálicos (BQU-2003-01096).
Miembros del ICMA que participan en esta línea:
D. Carmona, M. P. Lamata, F. Viguri, J. Ferrer, M. Esteban
.
101
Relación estructura-actividad
metálicos polinucleares.
en
complejos
Esta
área
de
investigación
persigue
el
establecimiento de una relación entre la estructura molecular y electrónica-, de nuevos compuestos de
coordinación, generalmente polinucleares, y su
reactividad química o, en su caso, actividad catalítica.
Se pretende el diseño racional, a partir de los
estudios de naturaleza estructural, de nuevos
complejos multimetálicos con potencial reactividad
relevante en el entorno de la catálisis homogénea,
explotando el uso de ligandos puente polidentados.
Se trata de aportar información estructural para la
comprensión de los mecanismos por los que se
producen determinados procesos reactivos o
catalíticos, de acotar el procedimiento por el que se
verifican los efectos cooperativos entre centros
metálicos, así como de extender a la química
polinuclear la aplicación de aquellos efectos
electrónicos básicos de utilidad en química
mononuclear. Esta información se obtiene a partir de
estudios de estructura molecular y electrónica,
conjugando medidas experimentales de difracción,
con cálculos teóricos de química computacional de
distintos grados de precisión. Adicionalmente, esta
línea de trabajo dedica especial atención al estudio
de los empaquetamientos cristalinos, información
ésta de vital importancia en la identificación de
interacciones débiles de no-enlace, básicas, a su vez,
en procesos de reconocimiento molecular y de
aplicación en química supramolecuar y en ingeniería
cristalina.
Structure-activity
metal complexes.
relationship
in
polynuclear
This research area aspires to the establishment of a
relationship between the molecular and electronic
structure of new coordination,- generally polynuclear,complexes and their chemical reactivity and, in some
cases, their catalytic activity. Exploiting the use of
bridging polydentate ligands, our approach aims the
rational design –based on the structural knowledgeof multimetallic complexes with potential reactivity in
the field of homogeneous catalysis. We search for
structural information to understand particular reactive
or catalytic processes, to establish the mechanism by
which the cooperative synergetic effects take place
among metals, and to extend to polynuclear chemistry
the application of basic electronic effects of general
use in mononuclear chemistry. This information is
obtained from molecular and electronic structural
studies, putting together experimental diffraction
measurements
with
computational
theoretical
calculations carried out at different precision levels.
Additionally, this project also searches with special
interest the identification of non-bonding weak
interatomic interactions, basic information in the
understanding of intermolecular auto-assembling, and
with great application in supramolecular chemistry
and crystal engineering.
Publicaciones:
A. P. Martínez, M. P. García, F. J. Lahoz, L. A. Oro. The unexpected synthesis of rhodium(I) complexes with the 1(2´-pyridyl)-3-oxo-1-propenoxide anionic ligand. Inorg. Chem. Commun. 2002, 5, 254-258.
A. P. Martínez, M. P. García, F. J. Lahoz, L. A. Oro. The rhodium and iridium co-ordination chemistry of the
hemilabile hybrid ligand 1-pyridil-3-dimethylamino-2-propen-1-one. Inorg. Chim. Acta 2003, 347, 86-98.
M. A. F. Hernández-Gruel, J. J. Pérez-Torrente, M. A. Ciriano, A. B. Rivas, F. J. Lahoz, I. T. Dobrinovitch, L. A. Oro.
Synthesis, reactivity and catalytic activity of triangular ZrM2 (M=Rh, Ir) early-late heterobimetallic complexes.
Organometallics 2003, 22, 1237-1249.
Proyectos:
Complejos organometálicos polinucleares de rodio e iridio. Síntesis, estructura y reactividad (PB98-1598).
Relación estructura/reactividad en complejos polinucleares de rodio e iridio (BQU2002-01729).
Miembros del ICMA que participan en esta línea:
F. J. Lahoz, M. P. García, F. J. Modrego, J. A. López, I. T. Dobrinovitch, A. P. Martínez, A. Balana.
102
Diseño de nuevas reacciones promovidas por
complejos de metales de transición. Aplicaciones
en catálisis homogénea.
Design of new reactions promoted by transition
metal complexes. Applications in homogeneous
catalysis.
Usando como plantillas complejos de coordinación de
metales de transición se pretende, a través de
sucesivas reacciones de acoplamiento carbonocarbono y carbono-heteroátomo, la síntesis de
moléculas orgánicas funcionalizadas a partir de
hidrocarburos básicos.
Esta línea se centra principalmente en la preparación
de nuevos compuestos polihidruro y en el estudio de
su reactividad frente a moléculas orgánicas
insaturadas (alquinos, olefinas, cetonas, …), en la
preparación de compuestos con ligandos carbono, en
la síntesis de complejos con una función hemilábil, y
en reacciones de ciclohidroaminación
Se buscan nuevos catalizadores homogéneos para
reacciones
conocidas
como
por
ejemplo,
polimerización de α-olefinas, oligomerización y
polimerización de alquinos, dehalogenación de
compuestos orgánicos, hidroaminación de alquinos y
olefinas, etc.
Using as a template coordination complexes of
transition metals (M) we intend, following successive
reactions of carbon-carbon and carbon-heteroatom
coupling reactions, the synthesis of functionalized
organic molecules starting from basic hydrocarbons.
This research line is focused mainly in the preparation
of new polyhydride complexes and the study of their
reactivity towards unsaturated organic molecules
(alkynes, olefines, ketones, …), in the preparation of
compounds with carbene ligands, in the synthesis of
complexes containing an hemilabil function, and in
cyclohydroamination reactions.
We are looking for new homogeneous catalysts for
known reactions such as α-olefin polymerization,
oligomerization and polymerization of alkynes,
dehalogenation
of
organic
compounds,
hydroamination of alkynes and olefins, etc.
Publicaciones:
M. A. Esteruelas, A. I. González, A. M. López, E. Oñate. An Osmium-carbene complex with Fischer-Schrock
ambivalent behaviour. Organometallics 2003, 22, 414-425.
M. L. Buil, M. A. Esteruelas, A. M. López, E. Oñate. C-N and C-C coupling reactions: Preparation of new nheterocyclic Ruthenium derivatives. Organometallics 2003, 22, 162-171.
M. A. Esteruelas, A. M. López, L. Méndez, M. Oliván y E. Oñate. Preparation, structure, and ethylene polymerization
behavior of bis(imino)pyridyl Chromium(III) complexes. Organometallics 2003, 22, 395-406.
Proyectos:
Reacciones estequiométricas y catalíticas de acoplamiento carbono-carbono y carbono-heteroátomo promovidas por
complejos de metales de transición (BQU2002-00606).
Nuevos catalizadores homogéneos para la hidrogenación de dobles enlaces de polímeros o copolímeros de dienos
conjugados (PPQ2000-0488-P4-02).
Nuevos catalizadores para la polimerización de α-olefinas (Repsol Petróleo, S. A.)
Miembros del ICMA que participan en esta línea:
M. A. Esteruelas, A. M. López de Lama, M. L. Buil, M. Oliván, E. Oñate, E. Royo, F. J. Fernández, A. Asensio, T.
Bolaño, B. Eguidor, A. I. González, Y. Hernández, A. C. Mateo.
103
Aminoácidos y péptidos
Amino acids and peptides
El primer objetivo del grupo de investigación consiste
en desarrollar nuevas metodologías para la síntesis
diastereoselectiva de aminoácidos y otros productos
de interés biológico en forma enantiopura con buenos
rendimientos y selectividades y usando productos de
partida sencillos y económicos. Para ello, se estudian
diferentes tipos de reacciones como adición de
nucleófilos sobre iminas quirales, alquilación de
enolatos y reacciones de cicloadición. Estas
metodologías han permitido la síntesis de numerosas
familias de compuestos de interés biológico en forma
enantioméricamente pura. El segundo objetivo
consiste en aplicar las estrategias necesarias para
desarrollar la síntesis en forma enantiopura de
diferentes tipos de aminoácidos conformacionalmente
restringidos cuidadosamente seleccionados para ser
incorporados en péptidos modelo con el propósito de
conocer sus tendencias conformacionales y
correlacionar así la restricción impuesta al
aminoácido con el tipo de estructura adoptada por el
péptido. En la actualidad, la atención está centrada
en análogos restringidos de fenilalanina pero está
previsto ampliar el estudio a derivados de prolina y
otros aminoácidos relacionados. Ya que es necesario
disponer de ambos enantiómeros del aminoácido y
en cantidades significativas, se recurre a la utilización
de procedimientos de resolución, fundamentalmente
HPLC en fases estacionarias quirales, sobre
precursores
racémicos
de
los
aminoácidos
necesarios.
Finalmente,
se
contempla
la
incorporación de alguno de estos aminoácidos
restringidos en un péptido de interés biológico.
The research group is first devoted to the
development of new methodologies to the
diastereoselective synthesis of amino acids and other
products of biological interest in enantiomerically pure
form with high yields and selectivities and starting
from easily available materials. To this aim, different
reactions such as nucleophilic addition on chiral
imines, diastereolective alkylation of enolates and
cycloaddition reaction are used. These methodologies
have allowed the synthesis of several families of
biologically interesting compounds in enantiomerically
pure form. Next, the appropriate methodologies are
applied to the synthesis, in enantiomerically pure form
of selected conformationally restricted amino acids.
These constrained amino acids are incorporated into
model peptides to determine their conformational
tendencies and thus establish a correlation between
the restriction introduced on the amino acid and the
structure accommodated by the peptide. This study is
presently directed to the constrained phenylalanine
analogues and will continue with proline derivatives
and other related constrained amino acids. Since for
this purpose significant amounts of both enantiomers
of the amino acid are required, the synthesis is
performed by resolution of a racemic precursor using
mainly HPLC on chiral stationary phases. Finally, the
incorporation of some of these restricted amino acids
into a biologically active peptide will be considered.
Publicaciones:
A. M. Gil, E. Buñuel, A. I. Jiménez, C. Cativiela. Stabilisation of the type I β-turn conformation by a bicyclic analogue
of proline. Tetrahedron Lett. 2003, 44, 5999-6002.
C. Peggion, F. Formaggio, M. Crisma, C. Toniolo, A. I. Jiménez, C. Cativiela, B. Kaptein, Q. B. Broxterman, M.
Saviano, E. Benedetti. Folding of peptides characterized by c3Val, a highly constrained analogue of valine.
Biopolymers 2003, 68, 178-191.
R. Badorrey, C. Cativiela, M. D. Díaz-de-Villegas, J. A. Gálvez. Highly convergent stereoselective synthesis of chiral
key intermediates in the synthesis of Palinavir from imines derived from L-glyceraldehyde. Tetrahedron 2002, 58,
341-354.
A. Avenoza, M. París, J. M. Peregrina, M. Alías, M. P. López, J. I. García, C. Cativiela. Aspartame analogues
containing 1-amino-2-phenylcyclopropanecarboxylic acids (c6Phe). Tetrahedron 2002, 58, 4899-4905.
Proyectos:
Nuevos aminoácidos en forma enantiomericamente pura. Diseño, síntesis e incorporación en péptidos con interés
estructural, industrial y/o biológico (PPQ2001-1834).
Miembros del ICMA que participan en esta línea:
C. Cativiela, M. D. Díaz de Villegas, J. A. Gálvez, M. P. López, A. I. Jiménez, R. Badorrey, M. Alías, A. M. Gil, M.
Lasa, R. Díez, S. Royo, G. Ballano, D. Aguirre, D. Casabona, P. Etayo.
104
Catálisis heterogénea en síntesis orgánicas
selectivas-procesos orgánicos sostenibles.
Heterogeneous catalysis in selective organic
syntheses-sustainable organic processes.
El grupo de investigación está interesado
especialmente en el desarrollo de procesos orgánicos
“verdes” mediante la búsqueda de reacciones más
eficientes (más selectivas y con menor gasto
energético) y más respetuosas con el medio
ambiente, utilizando reactivos y catalizadores menos
peligrosos.
Nuestro grupo ha preparado varios tipos de
catalizadores sólidos basados en arcillas, sílices,
óxidos mixtos, fosfatos y resinas orgánicas, con
propiedades ácidas o básicas. Estos catalizadores
pueden aplicarse eficientemente a diferentes
reacciones de formación de enlaces C–C y oxidación,
como la epoxidación de alquenos con H2O2. En la
mayoría de los casos, estos sólidos presentan una
elevada actividad catalítica, con una excelente
selectividad, y compiten ventajosamente con los
catalizadores tradicionales en disolución. En algunos
casos, inducen nuevas reacciones y permiten trabajar
en condiciones “verdes”, como en ausencia de
disolvente o con activación por microondas.
La inmovilización de catalizadores quirales para su
uso en síntesis enantioselectiva ha permitido obtener
catalizadores,
que
conjugan
una
alta
enantioselectividad con una reutilización fácil y
eficiente. La eficiencia del catalizador depende
esencialmente de la naturaleza del soporte y la
estrategia de inmovilización. La comprensión de la
influencia de estos factores está basada en el
mecanismo de reacción.
En los últimos años, se ha ampliado el campo de
investigación en Química Sostenible, con el estudio
de reacciones en líquidos iónicos, disolventes
interesantes y no volátiles, con un nulo impacto en la
atmósfera.
The research group is mainly concerned in the
development of green organic processes, by
searching for more efficient (more selective and less
energy-requiring) and more environment-respectful
reactions, using less hazardous reactants and
catalysts.
Several kinds of solid catalysts based on clays, silica,
mixed oxides, phosphates and organic resins with
acid or basic properties have been prepared by our
group. These catalysts can be efficiently applied to
different C–C bond forming and oxidation reactions,
such as alkene epoxidation with H2O2. In most cases,
these solids present a high catalytic activity, with an
excellent selectivity, and advantageously compete
with usual catalysts in solution. In some cases, they
promote new reactions and allow to work in green
conditions, such as no-solvent reactions or microwave
activation.
The immobilization of chiral catalysts for their use in
enantioselective Synthesis allowed to obtain excellent
catalysts, conjugating a high enantioselectivity with a
ready efficient reuse. Catalyst performance strongly
depends on the nature of the support and the
immobilization strategy, the understanding of the
influence of these factors being based on the reaction
mechanism.
In the last years, our research field in Green
Chemistry has been enlarged, with the study of
reactions in ionic liquids, interesting and non-volatile
neotheric solvents with negligible impact on the
atmosphere.
Publicaciones:
A. Cornejo, J. M. Fraile, J. I. García, M. J. Gil, G. Legarreta, S. V. Luis, V. Martínez-Merino, J. A. Mayoral. The first
immobilization of pyridine-bis(oxazoline) chiral ligands. Org. Lett. 2002, 4, 3927-3930.
J. M. Fraile, J. I. García, J. A. Mayoral, L. Salvatella, E. Vispe, D. R. Brown, G. Fuller. Experimental and theoretical
studies on structure-reactivity relationships of titanium-modified silicas in hydrogen peroxide-promoted oxidation of
cyclohexene. J. Phys. Chem. B 2003, 107, 519-526.
C. Cativiela, J. M. Fraile, J. I. García, B. Lázaro, J. A. Mayoral, A. Pallarés. Heterogeneous catalysis in the synthesis
and reactivity of allantoin. Green Chem. 2003, 5, 275-277.
Proyectos:
Síntesis de hidantoínas racémicas 5-sustituidas precursoras de aminoácidos ópticamente puros por vía enzimática
(PPQ2000-0322-P4-02).
Desarrollo de nuevos catalizadores enantioselectivos inmovilizados estables y reutilizables, basados en ligandos
procedentes de aminoalcoholes (PPQ2002-04012-C03-01).
Miembros del ICMA que participan en esta línea:
J. A. Mayoral, J. I. García, J. M. Fraile, L. Salvatella, E. Pires, C. Herrerías, E. Vispe, G. Lafuente, I. Villalba, I. PérezGrijalbo, R. Tahir.
105
Química bioorgánica
Bioorganic chemistry
El desarrollo de nuevas metodologías de producción
a
escala
de
laboratorio
de
compuestos
biológicamente activos que permitan resolver
problemas de interés biomédico es un objetivo
preferente dentro de la Química. La preparación
eficiente y selectiva, mediante procesos de Síntesis
Química,
de
diversas
biomoléculas
como
nucleósidos, carbohidratos y aminoácidos, así como
estructuras moleculares análogas, es fundamental
para alcanzar la diversidad funcional necesaria para
la realización de estudios suficientemente amplios
que lleven a resultados fiables.
La síntesis química de las moléculas objetivo, se
hace a través del estudio de reacciones químicas
sobre grupos funcionales que permitan elaboraciones
posteriores. Los procesos de adición nucleófila a
sistemas insaturados de tipo C=X, entre los que se
pueden incluir aldehídos, cetonas, nitronas,
hidrazonas e iminas adquieren gran importancia dada
su reactividad y los productos finales que
proporcionan.
El estudio de dichas reacciones químicas implica
también la utilización y puesta a punto de nuevos
métodos de síntesis que, además de aumentar la
eficiencia de los procesos, contribuyen al empleo de
condiciones no contaminantes y que pueden incluirse
dentro de la denominada Química Verde. Entre estos
métodos cabe destacar procesos de síntesis en fase
sólida,
química
combinatoria,
empleo
de
catalizadores, disolventes iónicos, etc.
Entre las actividades biológicas perseguidas
mediante los procesos de síntesis propuestos se
encuentran actividades antivirales, antitumorales y
antibióticas, principalmente. No obstante, el tipo de
compuestos que se preparan permite ampliar la
búsqueda a otras actividades relacionadas con la
terapeútica de enfermedades autoinmunes (artritis
reumatoide, Chron, etc.) o metabólicas (diabetes,
etc).
The development of new methodologies at a lab scale
leading to biologically active compounds with the aim
of resolving biomedic problems is a preferential
objective within Chemistry. The efficient and selective
preparation, through synthetic chemistry processes,
of several biomolecules, including nucleosides, carbohydrates and aminoacids, as well as, structural
analogues, must be pursued in order to raise the
functional diversity needed for carrying out reliable
studies.
The chemical synthesis of the target molecules
should be done through the study of the
corresponding chemical reactions on functional
groups allowing further chemical manipulations.
Nucleophilic addition reactions to unsaturated
systems of type C=X, such as, aldehydes, ketones,
nitrones, hydrazones and imines are important
processes because of their reactivity and the final
products obtained after treatment.
The study of those reactions also needs of new
synthetic methods that, in addition to increase the
efficiency of the processes, will contribute to the use
of clean conditions to be included into the so-called
Green
Chemistry.
Solid-phase
synthesis,
combinatorial chemistry, catalysis, use of ionic
solvents, etc. are examples of those methods.
Among the biological activities pursued by the
proposed synthetic methods are those leading to
antivirals, antineoplastic and antibiotic agents.
Nevertheless, the synthesized sort of compounds
allows the search for another interesting activities like
those related with autoimmune diseases (rheumatoid
arthritis, Chron, etc.) or metabolic dysfunctions
(diabetes, etc.).
Publicaciones:
P. Merino, J. Revuelta, T. Tejero, U. Chiacchio, A. Rescifina, G. Romeo. A DFT study on the 1,3-dipolar
cycloaddition reactions of C-(methoxycarbonyl)-N-methyl nitrone with methyl acrylate and vinyl acetate. Tetrahedron
2003, 53, 3581-3592.
P. Merino, S. Franco, D. Lafuente, F. Merchan, J. Revuelta, T. Tejero. Stereoselective synthesis of (-)Deacetylanisomycin. Eur. J. Org. Chem. 2003, 2877-2881.
P. Merino. Heterocyclic Nucleosides. Chemical synthesis and biological properties. Curr. Med. Chem. 2002, 1, 389411.
Proyectos:
Síntesis asimétrica de análogos de nucleósidos (BQU2001-2428).
Síntesis de agroquímicos modernos de especialidad para incidir en algunos parámetros de calidad de exportación en
los frutos (PROFIT-040000-2001-53).
Miembros del ICMA que participan en esta línea:
P. Merino, T. Tejero, S. Franco, F. L. Merchán, J. A. Matés, V. Mannucci, J. I. Delso, P. Romero
106
2.1.2.- Ciencia y Tecnología de Materiales
Materials Science and Technology
107
Propiedades ópticas lineales y no lineales de
moléculas y polímeros orgánicos.
Optical Properties of organic molecules and
polymers.
Una de nuestras líneas de investigación es el estudio
de las propiedades ópticas de polímeros, tanto
cristales líquidos (CLs) como amorfos para
aplicaciones ópticas, fundamentalmente en el campo
del almacenamiento óptico de información. Uno de
los objetivos es obtener películas de polímeros con
buenas características ópticas y cuyas propiedades
puedan modificarse ópticamente de forma controlada.
En particular, la presencia de grupos azobenceno,
cuya orientación es foto controlable, permite acceder
a dispositivos para almacenamiento digital y
holográfico de información. Un aumento espectacular
de la capacidad de almacenamiento se espera de la
holografía de volumen. La necesidad de disponer de
películas gruesas ha forzado el diseño de nuevos
materiales de partida. En particular,
se
ha
propuesto la utilización de polímeros bloque, en los
que las unidades fotocrómicas estén agrupadas en
dominios (de escala nanoscópica) separados unos de
otros; esto permite conservar la capacidad auto
organizativa de los CLs evitando los problemas de
dispersión de luz y de absorción asociada a elevadas
concentraciones de azobenzeno.
La búsqueda de materiales para aplicaciones ópticas
no lineales exige la caracterización de las unidades
básicas responsables de la respuesta no lineal (los
cromóforos) y la profundización en el estudio de las
relaciones estructura molecular-no linealidad. En
este campo, unos materiales muy atractivos son los
polímeros a los que se incorporan moléculas no
lineales. El estudio de su respuesta no lineal en
función de la composición y procesado completa esta
línea de investigación.
We are working on the study of optical properties of
liquid crystalline and amorphous polymers for optical
applications, mainly in the field of optical storage. One
of the aims is to obtain polymeric films with good
performances which optical properties can be
modified with light. In particular, the incorporation of
azobenzene groups and the photo control of their
orientation allow us to design optical devices for
digital and holographic storage. An enhancement of
the storage capacity is expected using volume
holography techniques. New materials must be
designed in order to prepare the required thick films.
In particular the use of block polymers has been
proposed. In these systems, the photo chromic units
are grouped (nanoscopic scale); the self-organizing
ability of LC polymers is guaranteed but the scattering
and absorption effects decrease.
The search of materials for non-linear optical
applications requires the characterization of nonlinear chromophores and the deep study of the
molecular structure-non linearity relationships. In this
field, the most interesting bulk organic materials are
polymers with non-linear moieties. The study of their
non-linear response as a function of the composition
and processing conditions is other of our research
lines.
Publicaciones
C. Sánchez, R. Alcalá, S. Hvilsted, P. S. Ramanujam. Effect of heat and film thickness on a photoinduced phase
transition in azobenzene liquid crystalline polyesters. J. App. Phys 2003, 93, 4454-4460.
J. L. Díaz, B. Villacampa, F. López-Calahorra, D. Velasco. Synthesis of polyconjugated Carbazolyl-Oxazolones by a
tandem hydrozirconation-Erlenmeyer reaction. Study of their hyperpolarizability values. Tetrahedron Lett. 2002, 43,
4333-4337.
R. Andreu, J. Garín, J. Orduna, R. Alcalá, B. Villacampa. Novel NLO-phores whit proaromatic Donor and Acceptor
groups. Org. Lett. 2003, 5, 3143-3146.
Proyectos
Polímeros funcionales para aplicaciones en óptica lineal y óptica no lineal. Proyecto coordinado con el dpto. de
Química Orgánica. CICYT (MAT2002-04118-C02-01).
Miembros del ICMA que participan en esta línea:
R. Alcalá, R. Cases, B. Villacampa.
109
Propiedades eléctricas, magnéticas y ópticas de
materiales compuestos cerámicos crecidos a
partir del fundido
Electrical, magnetic and optical properties of melt
growth ceramic composites
Además de sus excelentes propiedades mecánicas,
los materiales compuestos cerámicos crecidos a
partir del fundido (MGC), también presentan
interesantes características funcionales. Hemos
investigado algunas de estas posibles aplicaciones
funcionales de los materiales cerámicos de
composición eutéctica. Por ejemplo, hemos producido
láminas
delgadas
de
YBa2Cu3O7-δ
y
La1-xCaxMnO3-δ con texturas organizadas usando
como plantillas superficies escogidas de materiales
compuestos de óxidos con estructuras fibrosas o
laminares ordenadas. Compuestos laminares de
conductores iónicos y aislantes presentan una inusual
conducción iónica anisótropa. Hemos producido
mazos de fibras ópticas monocristalinas monomodo
2
con densidades de hasta 40000 pixels/mm en
materiales
compuestos
de
óxidos-fluoruros.
CERMETS monolíticos obtenidos de precursores
MGC presentan conducción mixta iónica-electrónica.
Se está investigando la utilización de algunos de
estos CERMETS en ánodos para pilas de
combustible. Cuando el tamaño de la fase es
comparable al de la longitud de onda emitida la
probabilidad de la transición de la misma depende del
tamaño característico de la microestructura. Hemos
explorado otras aplicaciones tales como las de
materiales compuestos ferromagnético-aislante o
monocristales con hasta un 50% de poro o fibras
monocristalinas de hasta 20 mm de longitud y 1 µm
de sección.
Como valor añadido a las investigaciones,
mencionemos que la mejora en las técnicas de
procesado de superficies mediante láser, ha
propiciado la contratación de proyectos de desarrollo
tecnológico.
In addition to their excellent mechanical properties,
melt growth ceramic composites (MGC) also exhibit
interesting functional characteristics. We have
explored some of such functional applications of
eutectic ceramic composites. For example, we
produced
patterned
YBa2Cu3O7-δ
and
La1-xCaxMnO3-δ thin films grown on selected surfaces
of lamellar or fibrous ordered oxide based
composites. Mixed ionic conducting and insulating
MGC´s with the lamellar structure presents highly
anisotropic ionic conduction. Bunch of singlecrystalline single-mode optical fibers with a density up
to 40.000 pixels/mm2 were produced in oxide-fluoride
composites. Monolithic CERMETS obtained from
MGC precursors presented mixed ionic-electronic
conductivity. Some of these porous CERMETS can
be used as solid oxide fuel cell (SOFC´s) anodes.
When the size of the phases is comparable to the
emission wavelength their lifetime depends on the
microstructure size. Other applications include highly
electrically
resistive
ferromagnetic-insulating
composites or 50% volume porous crystals or the
production of single crystal fibers up to 20 mm long 1
µm diameter for the first time.
As an added value to the proposed investigation, the
acquired knowledge of laser-processing procedures
has given rise to projects of technological
development.
Publicaciones
3+
R. I. Merino, J. A. Pardo, J. I. Peña, V. M. Orera. Microstructure size dependence of the 1.520 mm Er luminescence
lifetime in Al2O3-ZrO2 eutectic melt growth composites. Appl. Phys. Lett. 2002, 80, 589-591.
R. I. Merino, J. I. Peña, A. Larrea, G. F. de la Fuente, V. M. Orera. Melt grown composite ceramics obtained by
directional solidification: structural and functional applications. Recent Res. Devel. Mat. Sci. 2003, 4, 1-24.
R. I. Merino, J. I. Peña, M. A. Laguna-Bercero, A. Larrea, V. M. Orera. Directionally solidified calcia stabilised
zirconia-nickel oxide plates in anode supported solid oxide fuel cells. J. Eur. Ceram. Soc. 2004, 24, 1349-1353.
Proyectos
Fabricación de materiales funcionales laminares mediante fusión por zonas asistida por láser. (MAT2000-1495).
Advanced Ultra-Thin Ceramic Membranes for Efficient Industrial Processes (CERMOX). (CEE GRD-2000-25403).
Miembros del ICMA que participan en esta línea:
R. I. Merino, J. I. Peña, A. Larrea, M. A. Laguna, V. M. Orera.
110
Espectroscopía Raman de materiales de interés
tecnológico
Raman spectroscopy of materials of tecnological
interest
Se han estudiado mediante Espectroscopía Raman
tres tipos de materiales:
− Conductores iónicos para dispositivos
electroquímicos tales como baterías de litio y
pilas de combustible. Entre otros: perovskitas
conductoras de litio de tipo La(2-x)/3LixTiO3 y
bronces
protonados
La0.5(Li,Na)0.5TiO3;
HxNa1.2-xNb1.2W0.8O6;
óxidos
mixtos
Zr1-xCexO2. Aspectos estudiados: influencia
de tratamientos térmicos en la estructura;
orden local; movilidad del litio; inestabilidad
AFE; identificación de fases en muestras
procesadas mediante láser.
− Nanotubos de Carbono: propiedades físicas
básicas, atribución de bandas fonónicas en
relación con las relaciones de dispersión del
grafito;
caracterización
de
muestras
sometidas a diferentes tratamientos con
vistas a su utilización como materiales de
electrodo en supercondensadores.
− Semiconductores de tipo Zn1-xMnxGa2Se4.
Estudio de propiedades físicas a través de
su espectro vibracional.
We have studied with Raman spectroscopy three
kinds of materials:
− Ionic conductors for electrochemical devices
such as lithium batteries and fuel cells.
Among
others:
lithium-conducting
perovskites of type La(2-x)/3LixTiO3 and
protonated
bronzes
La0.5(Li,Na)0.5TiO3;
HxNa1.2-xNb1.2W0.8O6;
mixed
oxides
Zr1-xCexO2. Aspects studied are the influence
of thermal treatments in the structure, local
order, lithium mobility, antiferroelectric
instability, and phase identification in laserprocessed samples.
− Carbon nanotubes: physical properties,
attribution of phononic bands in relation with
dispersion
relations
of
graphite;
characterisation of samples submitted to
different treatments in view of their use as
electrode materials in ultracapacitors.
− Semiconductors of type Zn1-xMnxGa2Se4.
Study of physical properties through
measurement of their vibrational spectrum.
Publicaciones:
M. A. Laguna, M. L. Sanjuán, A. Várez, J. Sanz. Lithium dynamics and disorder effects in the Raman spectrum of
La(2-x)/3LixTiO3. Phys. Rev. B 2002, 66, 054301-7.
M. L. Sanjuán, M. C. Morón. Raman study of Zn1-xMnxGa2Se4 diluted magnetic semiconductors: disorder and
resonance effects. Physica B 2002, 316-317C, 565-567.
A. Várez, J. Ibarra, A. Rivera, C. León, J. Santamaría, M. A. Laguna, M. L. Sanjuán, J. Sanz. Influence of quenching
treatment on structure and conductivity of the Li3xLa2/3-xTiO3 series. Chem. Mater. 2003, 15, 225-232.
Proyecto:
Materiales conductores iónicos para dispositivos electroquímicos de producción y almacenamiento de energía.
MAT2001-3713-C04-02.
Miembros del ICMA que participan en esta línea:
M. L. Sanjuán, M. A. Laguna, P. Alonso-Gutiérrez.
111
Estudio de centros activos radicalarios y
metálicos en proteínas redox mediante técnicas
avanzadas de EPR
Esta línea de investigación se desarrolla en
colaboración, cada vez más intensa, con el grupo del
Prof. Picorel, de la Estación Experimental de Aula Dei
(CSIC), y con el grupo del Prof. Gómez-Moreno del
departamento de Bioquímica y Biología Molecular y
Celular de la Universidad de Zaragoza. El estudio de
la estructura electrónica de estos centros activos en
proteínas redox es de gran interés para determinar la
relación estructura-función de estos sistemas, los
cuáles están involucrados en diversas funciones en
los organismos vivos.
Mediante técnicas avanzadas de espectroscopía
EPR, especialmente 2D-ESEEM, es posible obtener
una información detallada de dicha estructura
electrónica; la espectroscopía HYSCORE es una
herramienta insustituible a la hora de obtener valores
de los tensores de acoplamiento hiperfino y
cuadrupolar con los núcleos magnéticos vecinos a la
entidad magnética. La información experimental en
metaloproteínas se contrasta con la obtenida en
compuestos modelo donde, mediante substitución
isotópica selectiva, es posible llevar a cabo una
asignación directa de las transiciones observadas a
núcleos específicos.
La información experimental así obtenida se combina
con la suministrada mediante cálculos DFT acerca de
la distribución de espín. De esta forma y mediante el
estudio de mutantes en los que se sustituyen
residuos del entorno del centro activo se obtiene
información acerca de la relación estructura-función.
Study of radical and metallic active centers in
redox proteins using advanced EPR techniques
This research line is developed in cooperation with
the prf. Picorel´s team (Estación Experimental de Aula
Dei, CSIC) and with prf. Gómez-Moreno´s group
(Biochemistry and molecular and cellular biology
department of the University of Zaragoza). The study
of the electronic structure of these active centers in
redox proteins is of great interests in order to
determine the structure - function relationship in these
systems, which are involved in diverse function of
alive organisms.
By advanced EPR spectroscopic techniques, mainly
2D-ESEEM, it is possible to get detailed information
about
this
electronic
structure:
HYSCORE
spectroscopy is an irreplaceable tool for obtaining the
hyperfine and quadrupolar coupling tensors with the
nuclei near to the magnetic entity. The experimental
information on the proteins is compared with that
obtain in model compounds where, using selective
isotopic substitution, it is possible to assigns the
observed transition to specific nuclei.
This experimental information is combined with that
about the spin distribution provided by DFT
calculation. In this way and by the study of mutants, in
which a substitution of residues near to the active
center takes place, information about the structure –
function is achieved.
Publicaciones:
J. I. García, M. Medina, J. Sancho, P. J. Alonso, C. Gómez-Moreno, J. A. Mayoral, J. I. Martínez. A theoretical
analysis of the electron spin density distribution of the flavin semiquinone isoalloxazine ring within the protein
environment. J. Phys. Chem. A 2002, 106, 4729-4735.
I. Yruela, I. García-Rubio, M. Roncel, J. I. Martínez, V. M. Ramiro, J. M. Ortega, P. J. Alonso, R. Picorel. Detergent
effect on cytochrome b559 Electron paramagnetic resonance signals in the photosystem II reaction center. Photoch.
Photobio. Sci. 2003, 2, 437-442.
I. García-Rubio, J. I. Martínez, R. Picorel, I. Yruela, P. J. Alonso. HYSCORE spectroscopy in the cytochrome b559 of
photosystem II reaction centre. J. Am. Chem. Soc. 2003, 125, 15846-15854.
Proyectos:
Estudio, mediante técnicas de resonancia paramagnética electrónica en onda continua y en el dominio temporal, de
citocromos de la cadena de transporte electrónico fotosintético (CONSI+D, DGA P111/2001).
Versatilidad del anillo de isoaloxazina como centro redox. Implicaciones en procesos de transferencia de electrones
entre proteínas (MCYT BQU2001-2520/).
Mecanismos moleculares de toxicidad y tolerancia inducidos por cobre en el aparato fotosintético de plantas
superiores. Un estudio en suspensiones de células fotosintéticas de soja como organismo modelo (CONSI+D, DGA
P015/2001).
Miembros del ICMA que participan en esta línea:
P. J. Alonso, J. Martínez.
112
Óxidos de metales de transición: Síntesis,
caracterización y técnicas de radiación de
sincrotrón.
La actividad realizada en el estudio de óxidos de
metales de transición se puede resumir en los
siguientes puntos:
i) Síntesis, caracterización estructural y magnética de
óxidos mixtos de Mn conocidos como manganitas. En
concreto se estudió el efecto del desorden en el
material magnetorresistivo La2/3Sr1/3MnO3, donde se
observó un desacoplo de las transiciones magnética
y eléctrica que ha sido caracterizado y explicado. Se
estudió la serie LaMn1-xMgxO3 donde se ha
establecido la existencia de un orden de largo
alcance entre el Mn y el Mg. Las propiedades
magnéticas se explican por el cambio de valencia del
Mn y el efecto de la dilución
ii) Preparación, caracterización estructural y
magnética de óxidos usados en los puntos iii) y iv)
junto con materiales conocidos como "perovskitas
dobles". Este estudio se realiza en colaboración con
el departamento de magnetismo del ICMA y se centra
en compuestos tipo A2MM'O6 (A=alcalino-térreo;
M=Fe, Cr; M'=Mo, Re) de gran interés por sus
aplicaciones en espintrónica. Hemos optimizados los
métodos sintéticos obteniéndo materiales con buena
respuesta a campos magnéticos bajos y compuestos
con los altos campos coercitivos (óxidos de Re).
iii) Uso de radiación de sincrotrón en el ESRF. En
concreto, a) experimentos de espectroscopia de
absorción de rayos X en cristales crecidos en nuestro
laboratorio de La1.5Sr0.5MnO4. b) Experimentos de
difracción anómala o resonante en el Fe3O4. c)
Experimentos de dispersión de neutrones en el ILL.
iv) Entre todos los trabajos, quisiéramos resaltar: a) El
estudio realizado sobre la transición de fase en el
LaMnO3 (compuesto base de las manganitas
magnetorresistivas) ha clarificado el papel de la
distorsión Jahn-Teller en las propiedades de estos
materiales. b) La investigación del ordernamiento de
carga en la magnetita (transición de Verwey) y en las
manganitas ha permitido establecer la ausencia de
ordenamiento iónico en estos materiales.
Transition metal oxides: Sintesis, characterization
and synchrotron radiation techniques.
The activity carried out in the study of transition metal
oxides can be summarized as follows:
i)Synthesis, structural and magnetic characterization
of the mixed oxides of Mn, the so-called manganites.
In particular, we studied the effects of disorder in the
properties of La2/3Sr1/3MnO3. We found that magnetic
and electrical transitions were non-coupled in some
compounds. Such a behaviour was characterized and
explained. We also studied the LaMn1-xMgxO3 series.
A long range Mn/Mg ordering was found. The
magnetic properties along the series were accounted
for by the continuous change of the Mn valence and
the dilution effect by a non-magnetic ion.
ii) Synthesis, structural and magnetic characterization
of the oxides used in the points iii) and iv) together
with materials denoted as “double perovskites”. This
study is performed in collaboration with the
department of magnetism in the ICMA. It is focused
in the A2MM'O6 compounds (A=Ba, Sr, Ca; M=Fe, Cr;
M'=Mo, Re) that are very promising for spintronic
applications. We have improved synthetic routes to
otain materials with a good response to low magnetic
fields. In addition, we have found new samples
showing either new transitions or new properties such
as large coercive fields (Re based oxides).
iii) Syncrotron radiation experiments at the ESRF in
Grenoble. a) X-ray absorption spectroscopy studies in
single crystals of La1.5Sr0.5MnO4 grown in our
laboratory. b) Resonant scattering experiments in
magnetite. c) Neutron diffraction experiments at the
ILL.
iv) Among our scientific results, the most stricking
points are: a) the study of the phase transition at high
temperature of LaMnO3 (mother compund for
magnetoresistive manganites) has clarified role of
Jahn-Teller distortion in the properties of these
materials. b) The research on the charge ordering in
magnetite (Verwey transition) and manganites has
allowed us to establish the lack of ionic ordering in
these materials in opposite to the previous believings.
Publicaciones:
M. C. Sánchez, G. Subías, J. García, J. Blasco. The cooperative Jahn-Teller phase transition in LaMnO3 studied by
x-ray absorption spectroscopy. Phys. Rev. Lett. 2003, 90, 045503.
J. Blasco, J. García, J. Stankiewicz. Effects of Ga doping in La2/3Sr1/3MnO3. Phys. Rev. B 2003, 68, 054421.
J. Blasco, C. Ritter, L. Morellón, P. A. Algarabel, J. M. de Teresa, D. Serrate, J. García, M. R. Ibarra. Structural,
magnetic and transport properties of Sr2Fe1-xCrxMoO6. Solid State Sciences 2002, 4, 651-660.
Proyectos:
Estudio de óxidos de valencia mixta y nanoestructuras de semiconductores: Síntesis, caracterización y aplicación de
las espectroscopias de rayos X (MAT2002-01221).
Síntesis y crecimiento cristalino de materiales magnetorresistivos. Estudio mágnetico, eléctrico, estructural y
electrónico (MAT99-0847).
Miembros del ICMA que participan en esta línea:
J. García, J. Blasco, G. Subías, M. C. Sánchez, M. G. Proietti, J. Herrero.
113
Desarrollo de la espectroscopía de absorción de
rayos-x y nuevas técnicas emergentes basadas
en la radiación de sincrotrón
Esta línea de investigación está encaminada al
desarrollo de la espectroscopía de absorción de
rayos-x y técnicas asociadas como herramientas de
caracterización de materiales.
Para ello, nuestra actividad se centra por un lado en
la demostración de la viabilidad de la técnica XANES
como sonda estructural. Para ello, se realizan
cálculos desde primeros principios de espectros de
absorción de rayos-x sin la intervención de ningún
parámetro libre o proceso de refino.
Por otra parte, intentamos establecer los límites de
aplicabilidad del dicroísmo magnético circular en la
absorción de rayos-x circular (XMCD) como
herramienta de caracterización magnética de
materiales. En particular, nuestra investigación se
centra en la aplicación de esta técnica al estudio del
magnetismo de materiales intermetálicos de tierrarara y metal de transición. Nuestro objetivo último
consiste en obtener la caracterización magnética de
los estados 5d y 4f del metal lantánido como paso
previo a la modelización de la interacción magnética
entre la tierra rara y el metal de transición.
Development of x-ray absorption spectroscopy
and new synchrotron radiation related techniques.
This research line is devoted to the development of xray absorption spectroscopy and its related
techniques as tools for materials characterization.
Our activity is focussed, on the one hand, into
demonstrating the capability of XANES as a structural
tool. To this aim we perform ab-initio calculations of xray absorption spectra without using any free
parameter or fitting procedure.
On the other hand, we try to determine which are the
limits of x-ray magnetic circular dichroism (XMCD) to
be used as a materials characterization tool. In
particular our XMCD research is focussed into the
study of magnetism in rare-earth transition metal
intermetallic materials. Our aim to get the magnetic
characterization of both the 5d and 4f states of the
lanthanide metal as the first step to modelize the
magnetic interaction between the rare-earth and the
transition metal.
Publicaciones:
J. Chaboy, E. Cotallo, S. Quartieri, F. Boscherini. New opportunities in trace elements structural characterization:
High-energy X-ray absorption near-edge structure spectroscopy. J. Syncrotron Radiat. 2002, 9, 86-89.
J. Chaboy, C. Piquer. Modification of the magnetic properties of the R2Fe14B series (R= rare-earth) driven by
hydrogen absorption. Phys. Rev. B 2002, 66, 104433.
J. Chaboy, C. Piquer, N. Plugaru, H. Maruyama, N. Kawamura, M. Suzuki. Relationship between hydriding and Nd
magnetic moment in Nd2Fe14B. J. Appl. Phys. 2003, 93, 475.
Proyectos:
Materiales Magnéticos avanzados: síntesis, caracterización y aplicaciones (MAT99-0667-C04-04).
Desarrollo de nuevos materiales magnéticos de alto interés tecnológico: nuevas rutas de síntesis y de
caracterización microscópica (DGA-P004/2001).
Caracterización y aplicaciones de nuevos materiales nanoestructurados magnéticos (MAT2002-04178-C04-03).
Magnetismo y Radiación de Sincrotrón, Acuerdo de cooperación CICYT-INFN, CICYT.
Miembros del ICMA que participan en esta línea:
J. Chaboy, M. A. Laguna, C. Piquer
114
Nanoestructuras de semiconductores y técnicas
espectroscópicas con radiación de sincrotrón
Synchrotron
radiation
spectroscopy
semiconductor nanostructures.
El objetivo de esta línea de investigación es la
caracterización
mediante
espectroscopía
de
absorción de rayos-X (EXAFS, XANES) y difracción
anómala de rayos-X (DAFS), de hilos y puntos
cuánticos (QWrs, QDs) autoorganizados de
semiconductores III-V. Estos materiales, que
presentan nuevas propiedades asociadas a los
efectos cuánticos de confinamiento de los
portadores, constituyen la base de los nuevos
dispositivos electrónicos y optelectrónicos y de la
tecnología
de
las
telecomunicaciones.
El
conocimiento detallado de su estructura local, es
decir el estado de tensión, las propiedades elásticas,
la composición, es de fundamental importancia para
la comprensión y la mejora de sus propiedades
físicas.
Se realizan medidas de difracción anómala y
absorción en incidencia rasante (GIDAFS, GIXAFS),
de hilos cuánticos de InAs crecidos de forma
autoorganizada por epitaxia de haces moleculares
(MBE) en sustratros de InP(001). Se estudian
también puntos cuánticos de GaN/AlN crecidos
mediante técnica Stranski-Krastanov modificada,
sobre sustratos de SiC.
El objetivo es obtener un mapa el estado de tensión y
la composición de las nanoestructuras.
Esta línea de investigación se está desarrollando en
colaboración con el laboratorio SP2M del CEA
(Commissariat à l'Energie Atomique) de Grenoble y
es objeto de una acción integrada hispano francesa
(MCYT). Las muestras se fabrican en el laboratorio
MBE del CEA de Grenoble y en el Instituto de
Microelectrónica de Madrid.
Los últimos resultados obtenidos en los QWrs de
InAs han sido objeto del ESRF Highlights 2003 y
están en via de publicación en el Physical Review
Letters.
The aim of this research activity is to characterize, by
means of X-ray absorption spectroscopy (EXAFS,
XANES)
and
Anomalous
Diffraction
X-ray
spectroscopy (DAFS), self-assembled semiconductor
Quantum Dots (QDs) and Quantum Wires (QWrs).
These materials provide new physical properties
related to the carriers confinement at a quantum size
scale and they are the base of the novel electronic
and optoelectronic devices for telecommunications.
A detailed knowledge of their local structural
properties, i.e. lattice strain, elastic properties, size,
composition etc., is of major importance to better
understand and improve their physical properties.
We carry out X-ray anomalous diffraction and
absorption, in the grazing angle geometry (GIDAFS;
GIXAFS), of auto-organized InAs QWrs grown by
Molecular Beam epitaxy (MBE) onto InP(001)
substrates. We also study GaN/AlN QDs, grown by
MBE modified Stranski-Krastanow technique, onto
SiC substrates. Our goal is to obtain a map of the
nanostructures strain and composition.
This research activity is being developed in
collaboration with the SP2M group of CEA
(Commissariat à l'Energie Atomique) of Grenoble
and is supported by a French-Spanish agreement
(MCYT). The samples are grown in the MBE
laboratories of CEA in Grenoble and of the Instituto
de Microelectrónica in Madrid.
The last results obtained on the InAs Qwrs have
already appeared as EFSR Highlights 2003 and are in
press on Physical Review Letters.
of
Publicaciones:
S. Grenier, M. G. Proietti, H. Renevier, L. González, J. M. García, J. García. Grazing incidence diffraction anomalous
fine structure of InAs/InP(001) self-assembled quantum wires. Europhys. Lett. 2002, 57, 499.
H. Renevier, S. Grenier, S. Arnaud, J. F. Bérar, B. Caillot, J. L. Hodeau, A. Letoublon, M. G. Proietti, B. Ravel.
Diffraction anomalous fine-structure spectroscopy at beamline BM2 at the european Synchrotron radiation facility. J.
Syncrotron Radiat. 2003, 10, 435.
H. Renevier, M.G. Proietti, S. Grenier, G. Ciatto, L. González, J. M. García, J. M. Gérard, J. García. Glancing angle
EXAFS of encapsulated self- assembled InAs/InP quantum wire and InAs/GaAs Quantum Dots. Mat. Sci. Eng. 2003,
101, 174.
Proyectos:
Estudio de óxidos de valencia mixta y nanoestructuras de semiconductores: Síntesis, caracterización y aplicación de
las espectroscopias de rayos X (MAT2002-01221).
Síntesis y crecimiento cristalino de materiales magnetorresistivos. Estudio mágnetico, eléctrico, estructural y
electrónico (MAT99-0847).
Acción integrada hispano-francesa (HF- 2002-0078).
Miembros del ICMA que participan en esta línea:
M. G. Proietti, J. García.
115
Efectos de tamaño en nanoimanes
Size effects in nanomagnets
Estudiamos la variación de propiedades físicas de
nanomoléculas, partículas o hilos, que contienen
entre unos pocos átomos y muchos miles, autoorganizados en retículas de 2- y 3-dimensiones,
utilizando
nuevas
técnicas
experimentales
desarrolladas ex-profeso para este estudio. Una de
las propiedades de mayor interés tecnológico es la
anisotropía magnética, puesto que determina la
estabilidad de la imanación frente a las fluctuaciones
térmicas y, por tanto, si el nanoimán puede actuar o
no como unidad de información. Hemos encontrado
que la K de nanopartículas de Co aumenta
enormemente al disminuir su tamaño. Combinando
medidas magnéticas y de dicroismo con radiación de
sincrotrón, hemos mostrado que este fenómeno se
debe a la no compensación del momento orbital L de
los átomos situados en la superficie de las
nanopartículas. Además K y L dependen de las
propiedades electrónicas (conductor, aislante) de la
matríz en la que están embebidas las partículas,
abriendo así una vía para aumentar su anisotropía y,
por tanto, la densidad de información que estos
materiales pueden almacenar. Estudiando multicapas
auto-organizadas de estas nanopartículas, hemos
encontrado también que la inversión de los
momentos magnéticos se ralentiza a medida que
aumenta la interacción dipolar magnética con
partículas vecinas. Hemos también propuesto un
sencillo modelo que da cuenta de los resultados
cuantitativamente.
Hemos medido los ciclos de histéresis magnética de
nanohilos de Fe con diámetro entre 12 y 50 nm a
diferentes temperaturas (desde 300 mK) y
velocidades de barrido del campo magnético. Para
realizar estas medidas utilizamos un sensor microHall, desarrollado en nuestro laboratorio, cuya
sensibilidad es ya cuatro órdenes de magnitud mejor
que la de un magnetómetro comercial SQUID.
Finalmente, hemos contribuido también a investigar el
primer cristal de moléculas-imán que se ordena a
largo alcance debido a las interacciones dipolares
entre moléculas.
We study fundamental parameters of nanomagnets
containing from a few atoms to a few thousand atoms,
self-organized in 2-D and 3-D lattices, often using
experimental techniques developed by us to optimise
the experiments. The magnetic anisotropy K is one of
the magnitudes with highest technological interest,
since it determines the stability of the particle
magnetic moment against thermal fluctuations, thus
also its application in magnetic recording. We have
found that K of Co nanoparticles increases
enormously as the particle size decreases. By
combining magnetic measurements and magnetic
dichroism with synchrotron radiation, we have shown
this phenomenon to be directly linked to the presence
of uncompensated orbital moments L at the particle’s
surface. A very interesting discovery is that K and L
depend on the electronic properties (insulating or
metallic) of the matrix that surrounds the particles,
which opens the possibility to tailor their anisotropy,
thus also increasing the density of information they
are able to store. By studying self-organized arrays of
these nanoparticles, we have also found that dipolar
interactions with neighboring particles slow down the
magnetic relaxation process. We have also proposed
a simple theoretical model that quantitatively accounts
for these results.
We have also measured the magnetic hysteresis
loops of magnetic nanowires (between 12 and 50 nm
wide) as a function of temperature (from 300 mK) and
field sweeping rate. This is done with a micro-Hall
magnetometer developed in our laboratory that
already has a sensitivity four orders of magnitude
better than a commercial SQUID magnetometer.
Finally, we have also contributed to the discovery of
the first crystal of single-molecule magnets that shows
a transition to long-range magnetic order induced
solely by the weak dipolar interactions between
molecular spins.
Publicaciones:
F. Luis, J. M Torres, L. M. García, J. Bartolomé, J. Stankiewicz, F. Petroff, F. Fettar, J. L Maurice, A.Vaurès.
Enhancement of the anisotropy of nanometer-sized Co clusters. Phys. Rev. B 2002, 65, 094409.
F. Luis, F. Petroff, J. M. Torres, L. M. García, J. Bartolomé, J. Carrey, A. Vaurès. Magnetic relaxation of interacting
Co clusters: cross-over from two- to three-dimensional lattices. Phys. Rev. Lett. 2002, 88, 217205; Phys. Rev. Lett.
2002, 90, 059706.
A. Morelló, F. L. Mettes, F. Luis, J. F. Fernández, J. Krzystek, G. Aromí, G. Christou, L. J. de Jongh. Long-range
ferromagnetic dipolar ordering of high-spin molecular clusters. Phys. Rev. Lett. 2003, 90, 017206.
Proyectos:
“Imanes Macroscópicos y Nanométricos” de Ministerio de Ciencia y Tecnología (MAT2002-166).
Grupo Consolidado IMANA (Departamento de Ciencia, Tecnología y Universidad DGA).
Miembros del ICMA que participan en esta línea:
J. Bartolomé, F. Luis, L. M. García, F. Bartolomé, J. Stankiewicz, A. Camón, R. López
116
Propiedades magnéticas y de transporte eléctrico
de intermetalicos de tierra rara y metal de
transición
Magnetic and electrical transport properties of
rare earth and transition metal intermetallic
compounds
Las fases intermetálicas magnéticas de tipo R2Fe14B,
R2Fe17 y RFe12-xMx, donde R es una tierra rara y M –
metal de transición, son de gran interés tanto para el
estudio básico como para la investigación aplicada de
imanes permanentes. Hemos estudiado los efectos
de introducción de átomos ligeros tales como H, C y
N sobre propiedades estructurales y magnéticas de
compuestos R2Fe17 y R2Fe14B. Igualmente ha sido
investigado el efecto de sustitución parcial de R por
un ion nomagnético en Nd2Fe14B. El rol de los
estados 5d en intermetálicos RFe11.3W0.7 ha sido
determinado mediante espectroscopia Mössbauer y
medidas magnéticas. Este estudio ha sido apoyado
por cálculo de bandas que aportan los valores
esperados de momentos magnéticos y campos
hiperfinos en compuestos medidos.
Hemos sintetizado y caracterizado estructuralmente
y magnéticamente nuevos materials de tipo
Rm+nT5m+3nB2n que son imanes permanents con
propiedades interesantes.
Finalmente, a través de medidas experimentales de
la conductividad eléctrica, del efecto Hall y de la
imanación, hemos estudiado la interrelación entre
transporte electrónico y magnetismo en varios
compuestos intermetálicos.
Intermetallic magnetic phases of type R2Fe14B,
R2Fe17 and RFe12-xMx, where R is a rare earth
element and M – transition metal atom, are of great
interest for basic research as well as for applications
as permanent magnets. The effects of interstitials
such as H, C and N on structural and magnetic
proerties of R2Fe17 and R2Fe14B have been studied.
We have also investigated partial substitution of R by
nonmagnetic ion in Nd2Fe14B. The role of 5d states in
RFe11.3W0.7 intermetallic compounds has been
determined by Mössbauer spectroscopy and
magnetic measurements. This study has been
backed by band calculations which yield values of
magnetic moments and hyperfine fields for the alloys
studied.
We have synthesized and performed structural and
magnetic characterization of new materials of type
Rm+nT5m+3nB2n, which are attractive as permanent
magnets.
Finally, electrical conductivity, Hall effect and
magnetization measurements enabled us to establish
some of reciprocal effects between electronic
transport and magnetic state of various intermetallic
alloys.
Publicaciones
J. Bartolomé, S. Mukherjee, C. Rillo, N. Plugaru, C. Piquer. Magnetic relaxation phenomena in R2Fe17 (R=Y, Dy, Er y
Ho) and C and H derivatives. J. Alloy. Compd. 2003, 356-357 C, 208-210.
J. Stankiewicz, J. Bartolomé. Magnetic scattering in RMn12-xFex alloys. Phys. Rev. B 2003, 67, 092409.
N. Plugaru, J. Rubín, J. Bartolomé, C.Piquer, M. Artigas. Magnetic properties of RFe11.3W0.7 (R= Dy, Ho, Er and Lu):
On the R-Fe exchange inmteraction in the R(Fe,T)12 class of compounds. Phys. Rev. B 2002, 65, 134419.
Proyectos:
Imanes macroscópicos y nanométricos (MAT2002-166).
Motores con imanes permanentes: Optimización dinámica, evaluación de la corrosión de los imanes y nuevos
procesos de preparación de materiales para imanes permanentes (MAT2000-0107-P4-02).
Estudio de los efectos de la corrosión en imanes permanentes y de las pérdidas ac en cintas e hilos
superconductores, mediante la aplicación de campos magnéticos alternos de intensidad media (0,1 T) (DGA
PO18/2001).
Grupo Consolidado IMANA (Departamento de Ciencia, Tecnología y Universidad DGA).
Miembros del ICMA que participan en esta línea:
J. Bartolomé, J. Stankiewicz, J. Rubín, A. Camón, N. Plugaru, C. Piquer
117
Metrología cuántica
Quantum metrology
Nuestro grupo mantiene una gran tradición en el
desarrollo de instrumentación no comercial para su
uso en Metrología Cuántica eléctrica. El TPYCEA
(Madrid) es el usuario de esta instrumentación que da
servicio a la industria española. Durante esta etapa
hemos
proporcionado
al
TPYCEA
nuevas
heteroestructuras de AsGa/AsGaAl caracterizadas a
bajas temperaturas (0,3K) y campos intensos (12T)
para su uso como patrón primario de resistencia
basado en el efecto Hall cuántico. Asimismo hemos
optimizado la instrumentación del puente de
resistencias basado en el Comparador Criogénico de
Corriente: por un lado, se ha diseñado y adquirido un
dewar de He de bajo consumo para aumentar el
tiempo de autonomía a una semana, por otro lado, se
han automatizado las medidas mediante el desarrollo
de programas basados en Labview.
Un fruto de nuestra colaboración con la universidad
de Twente y el laboratorio de metrología nacional
holandés (Nmi) ha sido la implementación de un CCC
con una relación lo suficientemente elevada
(1:30000) como para amplificar la corriente de un
dispositivo de ¨Single Electron Tunneling¨. Este
sistema ha sido un paso necesario para el desarrollo
futuro de un patrón cuántico de corriente.
Our group has traditionally worked on the
development of non-commercial instrumentation for
electrical Quantum Metrology. TPYCEA (Madrid) is
the user of this instrumentation that provides with a
service to the Spanish industry. We have supplied
TPYCEA
with
characterized
AsGa/AsGaAl
heteroestructures at 0.3K up to 12T; they will be used
as primary resistance standard based on the quantum
Hall effect. Even more we have optimised the
instrumentation of the resistance bridge based on the
Cryogenic Current Comparator: on one hand a low
consumption cryostat has been designed and
purchased, on the other hand labview programs have
been developed to automatize the measurements.
An achievement of our collaboration with the
university of Twente and the national metrology
laboratory in The Netherlands (Nmi) has been the
implementation of a CCC with a sufficient relation
(1:30000) for the amplification the current of a Single
electron Tunneling device. This system has been a
necessary step towards the development of a
quantum current standard.
Publicaciones
G. Rietveld, E. Bartolomé, J. Sesé, P. de la Court, J. Flokstra, C. Rillo, A. Camón. 1:30.000 cryogenic current
comparator with optimum squid readout. IEEE T. Instrum. Meas. 2003, 52, 621-625.
C. Rillo, J. Sesé, E. Bartolomé, J. Flokstra, A. Camón, G. Rietveld. On the sensitivity of cryogenic current
comparators: theory and experiments. Metrologia 2003 40, 51-56.
J. Sesé, E. Bartolomé, A. Camón, J. Flokstra, G. Rietveld, C. Rillo. Simplified calculus for the design of a cryogenic
current comparator. IEEE T. Instrum. Meas. 2003, 52, 612-616.
Proyectos:
Optimización y automatización de dos comparadores criogénicos de corriente (OTRI2003/366).
Miembros del ICMA que participan en esta línea:
C. Rillo, A. Camón, J. Sesé.
118
Simulaciones de sistemas magnéticos
Simulations of magnetic systems
Clusters magnéticos, como Fe8 y Mn12, que
constituyen
los
núcleos
de
moléculas
organometálicas, se comportan a bajas temperaturas
como grandes espines da magnitud dada. En
cristales, a baja temperatura, la relajación magnética
sólo puede ocurrir por medio del efecto túnel. Surge
la pregunta de si puede haber relajación hasta llegar
al orden magnético. La respuesta es afirmativa,
aunque a tasas de relajación que disminuyen como la
potencia cúbica de la fracción de la desviación típica
de los campos dipolares cubierta por la ventana
abierta al efecto túnel. Además, se ha elaborado una
teoría para la relajación anómala, que estaba sin
explicar. Se predice que la relajación: (a) está
controlada por el protocolo de enfriamiento previo a la
relajación; (b) está dirigida por la entropía (no por la
energía); (c) Evoluciona como la potencia p del
tiempo, siendo p=1/2, para Fe8, pero no así en
general; (d) la relajación cesa una vez que todos los
espines se han invertido por lo menos una vez,
mucho antes de alcanzar el equilibrio térmico.
Magnetic clusters, such as Fe8 and Mn12, that make
up the core of large organometallic molecules,
behave at low temperatures as large single spins. In
crystals, their magnetic relaxation can only take place
through magnetic quantum tunneling, at very small
temperatures. The question arises whether crystals of
such tunneling dipoles can relax all the way into a
magnetically ordered state. We have found that this
does indeed apeen, albeit at a rate that vanishes as
the cube of the fraction of the root mean square of the
dipolar fields that is covered by the tunneling window.
In addition, a theory for the previously unexplained
anomalous relaxation of Fe8 has been developed. It
predicts the relaxation: (a) is controlled by the cooling
protocol; (b) is entropy (not energy) driven; (c) evolves
a the p–th power of time, where p=1/2 for Fe8, but not
so in general; (d) the relaxation stops when all spins
in the system have flipped at least once, long before
equilibrium ensues.
Publicaciones
J. F. Fernández. Dipolar ordering of molecular magnetic clusters. Phys. Rev. B 2002, 66, 064423 .
J. F. Fernández. Simulation of quantum tunneling in an open system. Modeling of Complex Systems: Seventh
Granada Lectures, edited by J. Marro and P. Garrido (American Institute of Physics, N.Y., 2003) pp. 242-250.
J. F. Fernández, J. J. Alonso. Magnetization of single molecule magnets. Phys. Rev. Lett. 2003 91, 047702.
Proyectos:
Relajación magnética cuántica y diagrama de fases de sistemas de moléculas imán. (BFM2003-03919-C02-01)
Miembros del ICMA que participan en esta línea:
J. F. Fernández
119
Materiales moleculares magnéticos
Magnetic molecular materials
Esta línea se centra en el estudio del comportamiento
físico de materiales magnéticos constituídos por
moléculas magnéticas o que contengan un sustrato
molecular o polimérico que contribuya a configurar las
propiedades del material. De forma primordial
interesa el estudio de materiales constituídos por
radicales libres, los formados por moléculas de alto
espín y el de materiales con propiedades
multifuncionales, ópticas, magnéticas y eléctricas,
tales que permitan comportamientos opto-magnético,
magneto-resistivo, etc. Entre los materiales que se
vienen estudiando caben destacar compuestos
radicalarios basados en azufre, en cuyo estudio este
grupo es pionero, complejos radicalarios con metales
de transición, compuestos de coordinación con
equilibrio alto espín-bajo espín y líquidos orgánicos
paramagnéticos. El grupo utiliza, de manera habitual,
una gran variedad de técnicas: térmicas,
estructurales, magnéticas, grandes instalaciones para
experimentos basados en dispersión de neutrones o
implantación de muones, técnicas de presión, optomagnética, etc. Cuando el alto grado de innovación, o
la novedad, de una técnica hacen que no existan
instrumentos comerciales, éstos se desarrollan en el
propio grupo.
Los objetivos concretos son los siguientes:
− Búsqueda de nuevos imanes orgánicos con
temperaturas en la región del nitrógeno líquido o
superiores, donde los radicales basados en
azufre reciben un interes prioritario.
− Identificación
de
materiales
moleculares
susceptibles de modificar su ordenamiento
magnético mediante foto-excitación.
− Orden magnético en moléculas de alto espín.
− Estudio y caracterización de materiales
moleculares multifuncionales, en particular
imanes quirales.
− Preparación,
estudio
y
desarrollo
de
nanocomposites magnéticos poliméricos de
interés aplicado.
This research line is centered on the study of the
physical behavior of magnetic materials formed by
either molecules or a polymeric substrate which in
either case contributes to the material properties. Of
primary interest is the study of materials formed by
free radicals, high spin molecules and materials with
multifunctional properties, e.g. optic, magnetic and
electric, thus presenting behavior such as optomagnetic, magneto-resistive and other. Materials
currently investigated include sulfur-based free radical
compounds, in which study the group is a recognized
pioneer, organic radical-based transition-metal
compounds, transition compounds with high spin-low
spin equilibrium and paramagnetic organic liquids.
The research is carried on using a rather large variety
of physical techniques. The list includes thermal,
structural and magnetic techniques, the use of large
facilities for neutron scattering and muon implantation
experiments, and pressure, photomagnetic and
magneto-optic techniques. The Group also develops
its own technical equipment when it is not
commercially available due to its novelty or innovation
degree.
The following are specific goals:
− Search of new organic, metal-free, magnets with
ordering temperatures in the region of liquid
nitrogen and above, where S-based organic
radicals receive prioritary interest.
− Characterization of molecular materials that
modify their magnetic ordering under photoexcitation.
− Magnetic ordering in high spin molecules.
− Study and characterization of multifunctional
molecular materials, particularly quiral magnets.
− Preparation, study and development of polymer
magnetic nanocomposites of applied interest.
Publicaciones
A. Alberola, R. J. Less, C. M. Pask, J. M. Rawson, F. Palacio, P. Oliete, C. Paulsen, A. Yamaguchi, R. D. Farley. A
thiazyl-based organic ferromagnet. Angew. Chem. Int. Ed. 2003, 42, 4782-4785.
N. Moliner, L. Salmon, L. Capes, M. C. Muñoz, J. F. Létard, A. Bousseksou, J. P. Tuchagues, J. J. McGarvey, A. C.
Dennis, M. Castro, R. Burriel, J. A. Real. Thermal and optical switching of molecular spin states in the FeL[H2B(pz)2]2
spin crossover system (L=bpy, phen). J. Phys. Chem. B 2002, 106, 4276-7283.
J. Campo, J. Luzón, F. Palacio, A. Millán, G. J. McIntyre. Superexchange interaction enhanced through spin
delocalization in Rb2FeBr5.H2O as studied by polarized neutron diffraction. Polyhedron 2003, 22, 2297-2299.
I. Gilbert, A. Millan, F. Palacio, A. Falqui, E. Snoeck, V. Serin. Magnetic properties of maghemite nanoparticles in a
polyvinylpyridine matrix. Polyhedron 2003, 22, 2457-2461.
Proyectos:
Molecular magnetism: from materials towards devices (TMR Network ERBFMRXCT980181).
Materiales moleculares magnéticos. Comportamiento magnético de materiales moleculares y poliméricos. CICYT,
(MAT2000-1388-C03-03).
Materiales magnéticos funcionales: materiales moleculares y materiales intermetálicos. (MAT2001-3507-C02-02).
Síntesis y propiedades físicas de nanoimanes unimoleculares obtenidos mediante nuevos métodos de síntesis
(Proyecto CTP2002/REDES). Nanoimanes moleculares (MAT2002-00433).
Miembros del ICMA que participan en esta línea:
R. Burriel, J. Campo, M. Castro, J. L. Luzón, A. Millán, M. C. Morón, F. Palacio, A. Rodríguez, A. Urtizberea.
120
Propiedades térmicas de materiales
Thermal properties of materials
La respuesta de materiales al suministro de calor se
manifiesta, por una parte, en magnitudes estáticas
que dan cuenta del almacenamiento de esa energía y
se describen con variables termodinámicas como el
calor específico. Por otra parte, su propagación viene
caracterizada por la conductividad térmica.
Hemos desarrollado técnicas especiales de
calorimetría para el estudio de materiales:
calorimetría con fotoexcitación, con campo magnético
y en función de la orientación cristalina, efecto
magnetocalórico
en
condiciones
adiabáticas,
microcalorimetría de modulación y de relajación.
Los trabajos se centran en efectos termodinámicos y
transiciones de fase en materiales moleculares
magnéticos, materiales intermetálicos, imanes duros,
aislantes magnéticos y cerámicas. Se estudian
también transiciones estructurales, procesos de
orden-desorden y su relación con la estructura
cristalina. La conductividad térmica se estudia en
cerámicas superconductoras de alta temperatura y
materiales de interés tecnológico.
Entre los objetivos, se pretende determinar
termodinámicamente los procesos de ordenamiento y
transiciones en materiales magnéticos. Esto permite
deducir las interacciones y predecir su aptitud para
desarrollos tecnológicos. También se obtiene la
caracterización energética de materiales en los que
se pueden sintonizar varias funciones interactuantes:
magnética, eléctrica, óptica, estructural y térmica.
En concreto, se aplica a problemas de:
- Refrigeración
magnética
a
temperatura
ambiente.
- Activación óptica de estados magnéticos.
- Marcadores térmicos de estados biestables.
- Inducción de orden mediante luz, presión o
campo magnético.
The behaviour of materials upon the application of
heat is given by static magnitudes that take into
account the energy storage and are described by
thermodynamic variables like the specific heat. On the
other side, the heat propagation is characterised by
the thermal conductivity.
We developed special calorimetric techniques for the
study of materials: calorimetry under photo-excitation,
in the presence of applied magnetic fields and with
varying crystal orientation, magnetocaloric effect in
adiabatic conditions, modulation and relaxation
microcalorimetry.
Of primary interest are thermodynamic effects and
phase transitions in molecular magnetic materials,
intermetallic materials, hard magnets, magnetic
insulators and ceramic materials. Structural phase
transitions, order-disorder processes and their relation
with the crystal structure are also investigated.
Thermal conductivity is studied in high Tc
superconducting ceramics and other materials of
strong technological interest.
Among the goals we try to obtain the thermodynamic
determination of ordering processes and transitions in
magnetic materials. It allows the deduction of the
interactions and their suitability for technical
developments. Also the energetic characterization of
materials where several interacting functions can be
tuned: magnetic, electric, optic, structural and
thermal.
In particular they include:
- Magnetic refrigeration at room temperature.
- Photo-activation of magnetic states.
- Thermal indicators of bi-stable states.
- Ordering induction with light, pressure, or
magnetic field.
Publicaciones
N. Moliner, L. Salmon, L. Capes, M. C. Muñoz, J. F. Létard, A. Bousseksou, J. P. Tuchagues, J. J. McGarvey, A. C.
Dennis, M. Castro, R. Burriel, J. A. Real. Thermal and optical switching of molecular spin states in the FeL[H2B(pz)2]2
spin crossover system (L=bpy, phen). J. Phys. Chem. B 2002, 106, 4276-7283.
M. C. Gallardo, R. Burriel, F. J. Romero, F. J. Gutiérrez, E. K. H. Salje. Low-temperature calorimetric study of SrTiO3.
J. Phys. Condens. Mat. 2002 14, 1881-1886.
R. Burriel, E. Palacios, J. J. Melero, P. Ferloni. Orientational phase transition of (CH3)4NCIO4 in two and three
dimensions. Ferroelectrics 2002, 270, 393-398.
Proyectos:
Materiales magnéticos funcionales: materiales moleculares y materiales intermetálicos. (MCYT MAT2001-3507-C0202).
Phonon spectra, thermodynamic stability and phase transitions in perovskite-like crystals. (INTAS, RFBR-97-10177).
Caracterización del proceso de polimerización de pastas resistivas mediante calorimetria diferencial de barrido y
correlación con medidas eléctricas. (OTRI 2002-0297 con la empresa ACP S.A.)
Miembros del ICMA que participan en esta línea:
R. Burriel, M. Castro, F. Palacio, E. Palacios, A. Rodríguez, L. Tocado.
121
Estudio de sistemas
magnetoelectrónica
de
alto
interés
en
Una línea de investigación central dentro del área de
los materiales magnetoelectrónicos es la de los
sistemas magnetorresistivos, de aplicación en lectura
de información almacenada magnéticamente, en
sensores de campo magnético, en memorias no
volátiles, en potenciómetros de no contacto, etc. A
continuación,
enumeramos
los
sistemas
magnetorresistivos más interesantes que estamos
estudiando:
Óxidos
de
manganeso
que
presentan
magnetorresistencia colosal: nuestro estudio se
focaliza en la investigación de la relevancia de la
segregación de fases nanoscópica y microscópica en
el fenómeno de magnetorresistencia colosal.
- Dobles perovsquitas de alta temperatura de Curie
y polarización de espín: intentamos obtener
compuestos
que
muestren
una
elevada
magnetorresistencia a bajo campo hasta 200ºC
(temperatura máxima de trabajo de los dispositivos
en los que se pretenden aplicar) y comprender los
mecanismos que determinan la temperatura de Curie,
la
magnetorresistencia
y
los
fenómenos
magnetoestructurales.
- Uniones túnel magnéticas: investigamos los
parámetros que controlan la magnetorresistencia
túnel en este tipo de dispositivos.
- Partículas magnéticas nanométricas encapsuladas
en materiales orgánicos y otras matrices: queremos
conseguir el encapsulado efectivo de partículas
nanométricas magnéticas en diferentes matrices para
estudiar su respuesta magnetorresistiva y su
comportamiento magnético.
- Composites de partículas magnéticas y polímeros:
fabricamos composites de fácil procesabilidad y
compatibles con la tecnología actual en la industria
de los potenciómetros buscando efectos de elevada
magnetorresistencia a bajo campo hasta 200ºC.
Study of systems
magnetoelectronics
of
high
interest
in
A central research line in the area of the
magnetoelectronic
materials
is
that
of
magnetoresistive systems, of wide application in the
reading of information stored magnetically, in
magnetic sensors, in non-volatile memories, in
contact-less potentiometers, etc. In the following, we
cite the most interesting magnetoresistive systems
currently studied by us:
Manganese
oxides
showing
colossal
magnetoresistance: our study focuses on the
relevance of the nanoscopic and microscopic phase
segregation to the colossal magentoresistance
phenomena.
- Double perovskites with high Curie temperature and
spin polarization: we are trying to obtain compounds
exhibiting high magnetoresistance ratios at low
magnetic fields up to 200ºC (maximum working
temperature of the devices where they will be used)
and understand the mechanisms that determine the
Curie temperature, the magnetoresistance and the
magnetostructural phenomena.
- Magnetic tunnel junctions: we investigate the
parameters that control the tunnel magnetoresistance
in this type of devices.
- Magnetic particles encapsulated in organic materials
and other matrices: we want to obtain the effective
encapsulation of nanometric magnetic particles in
different matrices in order to study the
magnetoresistive response and their magnetic
behaviour.
- Composites of magnetic particles and polymers: we
obtain composites easy to process and compatible
with the current technology in the industry of
potentiometers that show high magnetoresistance
ratios at low magnetic fields up to 200ºC as well as
understand
the
mechanisms
controlling
the
magnetotransport.
Publicaciones:
J. M. de Teresa, M. R. Ibarra, P. A. Algarabel, L. Morellón, B. García-Landa, C. Ritter, A. Maignan, C. Martin, B.
Raveau, A. Kurbakov, V. Trounov. Magnetic versus orbital polarons in colossal magnetoresistance manganites.
Phys. Rev. B Rapid Communications 2002, 65, 100403.
D. Serrate, J. M. de Teresa, J. Blasco, M. R. Ibarra, L. Morellón, C. Ritter. Large low-field magnetoresistance and TC
in polycrystalline (Ba0.8Sr0.2)2-xLaxFeMoO6 double perovskites. Appl. Phys. Lett. 2002, 80, 4573.
C. Martínez-Boubeta, J. M. de Teresa, J. L. Costa-Kramers, A. Cebollada, J. A. Anguita, F. Briones, D. Serrate, J. I.
Arnaudas, M. R. Ibarra. Magnetic coupling in epitaxial in TM/MgO/Fe(001) (TM=FeCo, Fe/Co, Fe) macroscopic and
microscopic trilayers. J. Appl. Phys. 2003, 94, 4006.
Proyectos:
Advanced magnetic oxides for responsive engineering (G5RD-CT-2000-00138).
Estudio de sistemas magnetorresistivos de alto interés en magnetoelectrónica (MAT2002-04657).
Heteroestructuras híbridas con aplicaciones en magnetoelectrónica (MAT-2000-101290-C03-01).
Materiales masivos con relevantes propiedades magnetoelectrónicas: intermetálicos y óxidos laminares (MAT-20001756).
Spin, charge and orbital ordering in complex transition metal oxides: an integrated synthesis and measurement
approach (SCOOTMO) (HPRN-CT 2002 00293).
Miembros del ICMA que participan en esta línea:
M. R. Ibarra, P. A. Algarabel, C. I. Marquina, L. Morellón, J. M. de Teresa, D. Serrate, C. Magén.
122
Intermetálicos
relevantes
con
propiedades
magnéticas
El objetivo de la presente línea de investigación es el
estudio de materiales masivos con relevantes
propiedades físicas que hagan posible su uso
tecnológico. La actividad realizada en este campo se
centra fundamentalmente en dos familias de
compuestos: TR5(SixGe1-x)4 (TR= Tierra Rara) y
Ni2+xMn1+yGa1+z. Ambas series de compuestos
presentan transiciones magnéticas y estructurales
cuyas temperaturas pueden controlarse a partir de las
composiciones
relativas
de
los
elementos
constituyentes. Cuando las temperaturas de las
transiciones magnética y estructural coinciden
(transición magneto-estructural de primer orden) es
posible, mediante la aplicación de campos
magnéticos relativamente débiles, inducir la transición
maximizándose en dicho rango de temperaturas
propiedades altamente interesantes para una posible
aplicación tecnológica de dichos compuestos. Entre
dichas propiedades es de destacar la aparición de
magnetoestricción, magnetorresistencia y efecto
magnetocalórico gigantes.
La investigación realizada en nuestro departamento
comprende
desde
la
preparación
de
los
intermetálicos mediante fusión en horno de arco
hasta su completa caracterización magnética y
estructural
mediante
técnicas
macroscópicas
(medidas de imanación y susceptibilidad ac,
dilatación térmica, resistividad, magnetoestricción y
magnetoresistencia) y microscópicas (difracción de
rayos X, difracción de neutrones y espectroscopía de
muones)
Study of systems
magnetoelectronics
of
high
interest
in
The aim of the research line about the present subject
is to study bulk materials with relevant physical
properties for technological applications. The
research in this field is mainly focused on two series
of compounds: RE5(SixGe1-x)4 (RE= Rare Earth) and
Ni2+xMn1+yGa1+z. Both series present magnetic and
structural transitions at temperatures that can be
controlled through the relative composition of the
constituent
elements.
When
the
transition
temperatures of both transformations coincide (firstorder magnetostructural transition), it is possible to
induce such a transition by applying moderate
magnetic fields. By doing so, it is possible to
maximize
relevant
magnetic
properties
(magnetostriction,
magnetoresistance
and
magnetocaloric effect) for potential technological
applications in the selected temperature range.
The research performed in our department includes
the preparation of the intermetallic samples using an
arc furnace, and their complete magnetic and
structural characterization by using both macroscopic
(magnetization and ac susceptibility, thermal
expansion,
resistivity,
magnetostriction,
and
magnetoresistance) and microscopic (X-ray and
neutron diffraction, and muon spin spectroscopy)
techniques.
Publicaciones:
C. Ritter, L. Morellón, P. A. Algarabel, C. Magén, M. R. Ibarra. Magnetic and structural phase diagram of Tb5(SixGe1-x)4.
Phys. Rev. B 2002, 65, 094405.
F. Albertini, L. Pareti, A. Paoluzi, L. Morellón, P. A. Algarabel, M. R. Ibarra, L. Righi. Composition and temperature
dependence of the magnetocrystalline anisotropy in Ni2+xMn1+yGa1+z (x+y+z=0) Heusler alloys. Appl. Phys. Lett.
2002, 81, 4032.
C. Magén, Z. Arnold, L. Morellón, Y. Skorokhod, P. A. Algarabel, M. R. Ibarra, J. Kamarad. Pressure-induced threedimensional ferromagnetic correlations in the giant magnetocaloric compound Gd5Ge4. Phys. Rev. Lett. 2003, 91,
2072002.
Proyectos:
Materiales masivos con relevantes propiedades magnetoelectrónicas: intermetálicos y óxidos laminares (MAT-20001756).
Miembros del ICMA que participan en esta línea:
M. R. Ibarra, P. A. Algarabel, C. I. Marquina, L. Morellón, J. M. de Teresa, D. Serrate, C. Magén.
123
Propiedades magnéticas y magnetoelásticas de
materiales nanoestructurados.
Magnetic and magnetoelastic
nanostructured materials.
El objetivo de esta línea de investigación es la
preparación y estudio de nuevos materiales
estructurados, bien en capas delgadas o multicapas,
bien
como
granulares
con
dimensiones
características nanométricas, y cuyas propiedades
pueden ser muy diferentes de las observadas en
materiales masivos: presencia de anisotropía
perpendicular al reducirse el espesor de la capa de
un metal magnético 3d o, en el caso de superredes
de Tierras Raras y películas epitaxiales, fases
magnéticas diferentes de las que existen en los
materiales masivos correspondientes y de cambios
en la anisotropía magnética.
Nuestras medidas de la tensión magnetoelástica en
función de la temperatura (300 K- 10 K) realizadas
mediante el uso del método “cantilever” indican que la
deformación interna es responsable de una
contribución adicional a la energía ME. Por ejemplo,
en el caso del níquel, el resultado es un incremento
en el valor de la coeficiente ME al aumentar la
deformación interna.
Medidas realizadas en nuestro laboratorio de
microscopia de fuerza magnética muestran una fuerte
variación, con el espesor de níquel, de la forma y
tamaño de los dominios magnéticos, debido a la
fuerte variación de la intensidad de la anisotropía
perpendicular. Esto se refleja tanto en el proceso de
imanación medido mediante magnetometría de
muestra vibrante como en el signo y valor de las
isotermas de tensión ME.
The aim of this research is the preparation and
magnetic characterization of new RE-based materials,
structured as thin films, multilayers and granular
systems, of nanometric characteristic size, whose
properties can be very different from those observed
in massive materials: perpendicular magnetic
anisotropy in 3d magnetic metals or, for Rare Earth
superlattices and thin films,
the different found
magnetic phases and substantially influences the
magnetic anisotropy.
Our measurements of the ME stress as a function of
the temperature (300 K- 10 K), performed by the
cantilever technique, indicate that the internal strain is
responsible of an additional contribution to the ME
energy. For example for Ni thin films, the issue is that
the ME stress coefficient increases as the internal
strain increases.
Masurements of the magnetic domains performed in
our laboratory by magnetic force microscopy show a
strong variation of the shape and size of the magnetic
domains with the Ni thickness due to the variation of
the anisotropy energy. This is also reflected in the
magnetization process studied by vibrating sample
magnetometry and in the sign and value of the ME
stress isotherms measured to determine the
magnetoelastic stress.
properties
of
Publicaciones:
M. Ciria, J. I. Arnaudas, L. Benito, C. de la Fuente, A. del Moral, J. K. Ha, R. C. O´Handley. Magnetoelastic effects in
thin films with weak out-of-plane anisotropy. Phys. Rev. B 2003, 67, 024429.
J. I. Arnaudas, C. de la Fuente, M. Ciria, L. Benito, C. Dufour, K. Dumesnil, A. del Moral. Magnetoelastic stresses in
epitaxial (110) Terfenol-D thin films. J. Magn. Magn. Mater. 2002, 240, 389-391.
L. Benito, C. de la Fuente, M. Ciria, J. I. Arnaudas, A. del Moral, C. Dufour, K. Dumesnil. Magnetoelasticity of singlecrystal (110) SmFe2 thin-film. J. Magn. Magn. Mater. 2002, 242, 1450-1452.
Proyectos:
Heteroestructuras híbridas con aplicaciones en magnetoelectrónica. (MAT2000-1290-C03-01).
Anisotropía magnética y magnetoelasticidad en capas finas de metales de transición. (HF02-167).
Magnetismo y magnetoelasticidad en láminas delgadas y en sistemas masivos fuertemente correlacionados.
(MAT2003-00893).
Miembros del ICMA que participan en esta línea:
A. del Moral, J. I. Arnaudas, C. de la Fuente, M. Ciria, L. Benito.
124
Compuestos cerámicos de altas prestaciones
mecánicas fabricados mediante fusión asistida
por láser
High
mechanical
performance
composites
fabricated
by
laser
solidification
ceramic
assisted
Los materiales cerámicos de alta resistencia
mecánica y tenacidad son de interés en aplicaciones
estructurales debido a su ligereza y estabilidad a alta
temperatura en atmósferas oxidantes. Estos atributos
son especialmente importantes en las turbinas de gas
ya que su uso aumenta la eficiencia de la combustión
lo que se traduce en un menor consumo y una
reducción en emisiones contaminantes. También se
aplican en abrasivos, superficies resistentes al
desgaste, como refuerzo en materiales compuestos,
etc. En esta línea investigamos sobre nuevos
compuestos cerámicos que puedan superar las
habituales limitaciones de las cerámicas que trabajan
a alta temperatura, mejorando su resistencia
mecánica, tenacidad y fatiga. Entre los materiales
explorados destacan los óxidos eutécticos obtenidos
a partir de la solidificación de sus fundidos. El control
de la microestructura mediante el procesado nos ha
permitido alcanzar valores de resistencia a flexión de
hasta 2,3 GPa en el caso de barras eutécticas del
sistema Al2O3/Y2O3 (Tm = 1826 ºC), reteniendo dicha
resistencia hasta por encima de 1500ºC. También
fabricamos laminados cerámicos mediante técnicas
de procesamiento cerámico combinadas con
tratamientos asistidos por láser para ser aplicados
como recubrimientos de substratos metálicos.
Utilizamos la fusión superficial por láser de
recubrimientos cerámicos fabricados mediante
proyección térmica para sellarlos contra la
penetración de agentes corrosivos durante el servicio
y mejorar la adherencia entre el substrato y el
recubrimiento. Las técnicas de caracterización de
estos materiales incluyen la microscopía óptica,
electrónica, difracción de rayos X, técnicas
espectroscópicas (Piezoespectroscopia, Raman) e
indentación disponibles en nuestro Instituto mientras
que los tests mecánicos se realizan en la Universidad
Politécnica de Madrid y la Universidad de Sevilla.
Ceramics with high resistance and toughness are of
interest for structural applications because of their
light weight and high temperature thermodynamic
stability even in an oxidant atmosphere. These
attributes are of particular importance in gas turbine
engines because of the increase in the combustion
efficiency and reduction in contaminant emissions.
They are also applied as abrasives, wear resistance
surfaces, reinforcing fibres, etc. The objective of this
line is the development of new ceramic compounds
overcoming the current performance limitations for
high temperature ceramics, e.g. strength, creep,
toughness and fatigue. Among the materials we have
explored it is worth mentioning the eutectic oxides
obtained from the melt. Tayloring the microstructure
by means of the processing conditions allows us to
reach strength values of 2.3 GPa for the bars in the
eutectic system Al2O3/Y2O3 (Tm = 1826 ºC) retaining
this strength up to above 1500 ºC. Layered ceramic
composites are produced by ceramic and laser
processing to be applied as ceramic coatings on
metal substrates. Laser glazing of plasma-sprayed
ceramic coatings is another subject of our interest,
arising from needs to seal coatings against
penetration by corrosive agents during operation and
to improve coating-substrate adherence. The
characterization procedures involve optical and
electronic microscopy, X-ray diffraction, spectroscopic
techniques
(piezospectroscopy,
Raman)
and
indentation available in our Institute. Mechanical tests
are performed in the Universidad Politécnica de
Madrid and the Universidad de Sevilla.
Publicaciones
N. R. Harlan, R. I. Merino, J. I. Peña, A. Larrea, V. M. Orera, C. González, P. Poza, J. Llorca. Phase Distribution and
Residual Stresses in Melt Grown Al2O3-ZrO2 (Y2O3) Eutectics. J. Am. Ceram. Soc. 2002, 85, 2025- 2032.
V. M. Orera, R. Cemborain, R. I. Merino, J. I. Peña, A. Larrea. Piezo-Spectroscopy at low Temperatures: Residual
Stresses in Al2O3- ZrO2 (Y2O3) Eutectic Measured from 77 to 350 K. Acta Mater. 2002, 50, 4677- 4686.
A. Larrea, G. F. de la Fuente, R. I. Merino, V. M. Orera. ZrO2 - Al2O3 eutectic plates produced by laser zone melting.
J. Eur. Ceram. Soc. 2002, 22, 191-198.
Proyectos
Procesado por láser de cerámicos estructurales avanzados. (P3)( MAT2000-1533-C03-02).
Miembros del ICMA que participan en esta línea:
J. I. Peña, A. Larrea, R. I. Merino, V. M. Orera, G. F. de la Fuente, C. Diez, I. de Francisco, P. B. Oliete.
125
Aplicaciones del láser en la transformación y
modificación de materiales.
Laser applications in the transformation and
modification of materials.
El objetivo fundamental del grupo es utilizar las
ventajas que ofrece la tecnología láser para
desarrollar métodos de procesado por láser que
incidan positivamente en el sector de la
transformación y modificación de materiales. El
conocimiento de los avances en tecnología láser, así
como de las propiedades químicas y físicas de
materiales de interés industrial, han permitido centrar
los esfuerzos del grupo en varias líneas de
investigación. Estas líneas se basan, a su vez, en la
utilización del láser en modo contínuo, para realizar
operaciones de calentamiento y fusión, o en modo
pulsante, para realizar trabajos de ablación.
En régimen continuo, el grupo estudia la utilización
de compuestos precursores organometálicos o de
coordinación, para realizar pirólisis y síntesis vía
combustión. También se estudia el corte de
materiales mediante fusión y expulsión del fundido
por gas a presión. Finalmente, se utiliza el láser en
configuraciones que permiten fundir y solidificar
direccionalmente,
para
estudiar
reacciones
novedosas en estado líquido a temperaturas
extremas, o bien para obtener nuevos recubrimientos
basados en materiales con elevado punto de fusión.
En régimen pulsante, el grupo estudia la aplicación
de diversos procesos de ablación con objeto de, por
una parte, producir mecanizado y corte de metales y
cerámicas con mínimo daño y máxima flexibilidad.
Por otra, producir materiales nanoparticulados,
estudiando la interacción láser-precursor (o, en su
caso, preforma) y su efecto sobre la morfología,
microestructura y propiedades de los productos
obtenidos. Finalmente, se estudian procesos de
ablación para la descontaminación de superficies de
todo tipo, especialmente metálicas e inorgánicas
(pétreas, cerámicas), con el objeto de realizar
desarrollos de técnicas de alto rendimiento para la
conservación de objetos y edificaciones que forman
parte del patrimonio histórico-artístico y cultural
europeo.
The aim of this research group is to use the
advantages posed by laser technology to develop
laser processing methods which will have a positive
influence on the materials transformation and
modification
discipline.
Knowledge
on
laser
technology advances, as well as on the chemical and
physical properties of industrial materials, has allowed
the group to centre its efforts around several research
themes. These themes are based on the use of the
laser in cw mode, to perform heating and melting, or
in pulsed mode, to carry out ablation work.
In cw mode, the group studies the use of
organometallic and coordination complexes to study
pirolysis and synthesis via combustion. Cutting of
materials is also studied via melting and expulsion of
the melt under pressure. Finally, the laser is used
under cw mode to achieve melting and directional
solidification in systems which provide novel reactions
in liquid phase at extreme temperatures. Alternatively,
this method may be used to obtain new coatings
based on high melting point materials.
In pulsed mode, the group studies the application of
several ablation techniques with two objectives. On
the one hand, to achieve machining and cutting of
metals and ceramics with a minimal heat affected
zone (HAZ) under the most flexible conditions. On the
other hand, to produce nanoparticles, studying the
laser-precursor (or preform) material interaction and
its effect on final morphology, microstructure and
properties of the obtained materials. Finally, ablation
processes for surface (all types, specially stone and
ceramics) decontamination are also studied within the
group, in order to apply the technology to the
development of high yield laser methodology
applicable to the conservation of cultural heritage.
Publicaciones
E. Tejada-Rosales, S. Ondoño-Castillo, C. Diez, G. F. de la Fuente, N. Casañ-Pastor. Annealing of electrophoretic
YBa2Cu3O7 coatings on polycrystalline substrates by zonal laser fusion. Bol. Soc. Esp. Ceram. V 2002. 41, 185-189.
T. Seeger, G. F. de la Fuente, W. K. Maser, A. M. Benito, M. A. Callejas, M. T. Martínez. Evolution of multiwall
carbon-nanotube/SiO2 composites via laser treatment. Nanotechnology 2003, 14, 184-187.
Proyectos
Aplicación de métodos numéricos sin malla a la simulación de procesos de recubrimiento por láser (DPI2002-01986).
Vanguardia, tradición y
(02/COOPERA/ES1368).
nuevos
desarrollos
tecnológicos
en
la
cerámica
tradicional
aragonesa
Miembros del ICMA que participan en esta línea:
G. F. de la Fuente, C. I. López, R. Lahoz, V. Lennikov, L. C. Estepa, L. A. Angurel, M. Laguna, M. de Val.
126
Fabricación de materiales superconducores de
alta temperatura con técnicas de fusión zonal
inducida con láser en configuraciones de interés
tecnológico.
Fabrication of high temperature superconductors
materials in technological configurations using
Laser Floating Zone techniques.
We
have
developed
bulk
Bi2Sr2CaCu2O8
Se han desarrollado materiales masivos de
superconducting materials to be used in large scale
superconductores de la familia Bi2Sr2CaCu2O8 para
electric applications. In particular we have worked in
two different applications: hybrid current leads and
aplicaciones eléctricas de potencia. En particular se
resistive fault current limiters.
ha trabajado en dos aplicaciones: barras de
Thin rods have been used to develop hybrid current
alimentación híbridas y limitadores de corriente
leads prototypes for the DESY project. Basic studies
resistivos.
have been performed to demonstrate the possibility of
En el caso de las barras de alimentación híbridas se
using SIMPLEX algorithms to optimise the fabrication
han fabricado materiales para desarrollar prototipos
parameters of these materials. It has been found that
para el proyecto DESY. Desde el punto de vista
there is a strong correlation between the radial phase
fundamental se ha demostrado la viabilidad de utilizar
segregation that are induced during the solidification
métodos basados en algoritmos SIMPLEX para
process and the superconducting properties of these
optimizar los parámetros de fabricación. Se ha
materials.
establecido la fuerte correlación que existe entre la
The second application is based in the fact that the
segregación radial de fases que se produce durante
fault current limitation for high currents is one of the
el proceso de fusión y las propiedades
main application of these superconducting materials
superconductoras de estos materiales.
with a promising future. We will try to demonstrate
La segunda aplicación se basa en el hecho de que la
that these laser melting techniques can be used to
limitación de grandes intensidades de corriente es
obtain materials with high properties and with
una de las aplicaciones de los materiales
geometries that can be used for resistive fault current
superconductores y con un mercado definido y lleno
limiters. Two configurations are being developed:
de futuro.
Pretendemos demostrar que esta
planar with a meander configuration and cylindrical
tecnología de fusión zonal es válida para obtener
with helicoidal configurations.
These geometries
materiales de altas prestaciones en configuraciones
allow to obtaining materials with high lengths, a fact
que les permitan ser utilizados como limitadores de
that is important to obtain safe resistive fault current
corriente resistivos, bien sea en configuraciones
limiters. At the same time we are applying this
planas (en forma de meandro) o sobre soportes
technology to obtain superconducting thick films on
cilíndricos (caminos helicoidales). Estas nuevas
metallic and ceramic substrates using a tape casting
disposiciones son adecuadas para obtener grandes
or a dip coating technology.
longitudes y poder desarrollar limitadores de
One of the main problems of using high temperature
corriente. De forma simultánea, se está desarrollando
superconductors in fault currents limiters is the hot
una tecnología para depositar capas gruesas de
spot generation, which is associated to the ceramic
superconductores sobre soportes metálicos o
nature of these materials and their low thermal
cerámicos por la técnica de la cuchilla enrasadora o
conductivity. In order to overcome this problem, we
por inmersión.
have developed an electrodeposition technique that
Uno de los problemas de los materiales
allows to obtain metallic coatings on these ceramic
superconductores de alta temperatura para el
materials.
desarrollo de limitadores de corriente en la
generación de puntos calientes, que está asociado
intrínsecamente con su carácter cerámico y su baja
conductividad térmica. Para poder superar estos
problemas se ha desarrollado una técnica de
electrodeposición para fabricar recubrimientos
metálicos.
Publicaciones:
E. Natividad, M. Castro, R. Burriel, L. A. Angurel, J. C. Díez, R. Navarro. Correlation of normal and superconducting
state properties on textured Bi-2212 ceramic thin rods. Supercond. Sci. Technol. 2002, 15, 1022-1029.
E. Natividad, J. C. Díez, L. A. Agurel, J. M. Andrés, A. C. Ferrando, M. C. Mayoral. Radial changes in the
microstructure of LFZ-textured Bi-2212 thin rods induced by stoichiometry modifications. Physica C, 2003, 383, 379387.
M. Mora, J. C. Diez, C. I. López-Gascón, E. Martínez, G. F. de la Fuente. Laser textured Bi-2212 in planar
geometries. IEEE T. Appl. Supercon. 2003, 13, 3188-3291.
Proyectos:
Fabricación de materiales superconductores para aplicaciones eléctricas de potencia y análisis de los procesos de
degradación en servicio. (MAT2002-04121-C03-02).
European network for power application of superconductivity SCENET 2. (EU GCT-201-43047).
Miembros del ICMA que participan en esta línea:
R. Navarro, G. F. de la Fuente, L. A. Angurel, J. C. Díez, F. Lera, E. Martínez, M. Mora, A. Sotelo, E. Natividad, F.
Gimeno
127
Fabricación y caracterización de hilos y cintas de
MgB2.
Fabrication y caracterization of MgB2 wires and
tapes.
El
descubrimiento
de
superconductividad
a
temperaturas por debajo de 40 K en MgB2 a
principios del año 2001, abrió un campo nuevo de
materiales superconductores con temperaturas
críticas situadas entre los superconductores clásicos
y los superconductores de alta temperatura (SAT)
para su uso en aplicaciones a 20-25 K, fácilmente
alcanzables con criogeneradores. La novedad del
material, el bajo coste de los elementos que lo
forman, su baja anisotropía y las prestaciones
alcanzadas hasta el momento, dan un elevado interés
científico y técnico a su estudio.
El grupo de Superconductividad Aplicada del ICMA
está trabajando actualmente en el desarrollo,
optimización y análisis de hilos y cintas de materiales
compuestos metal/MgB2 con técnicas de polvo en
tubo (PET), usando diferentes forros metálicos tales
como Cu y Ni. La tecnología PET, ampliamente
investigada a escala de laboratorio y completamente
desarrollada a escala industrial en estos últimos años
para la fabricación de cintas Ag/PbBi-2223, se ha
empleado con éxito en la fabricación de hilos
compuestos metal/MgB2. En esta técnica, polvo de
MgB2 reaccionado o mezclas de Mg+2B sin
reaccionar, se empaquetan en el interior de un tubo
metálico, que posteriormente se trefila para conseguir
hilos o/y se lamina para la fabricación de cintas.
Finalmente, es necesario un tratamiento térmico en
ausencia de oxígeno para sinterizar o reaccionar el
polvo precursor. Obviamente, la elección del tubo
metálico es esencial, ya que éste debe conferir
estabilidad mecánica, térmica y eléctrica al
superconductor sin deteriorar sus propiedades.
La investigación se centra actualmente en conseguir
mejorar las prestaciones de estos materiales
fundamentalmente en dos aspectos: aumento del
anclaje de flujo que permita ampliar su rango de
aplicación a campos más elevados, así como en la
mejora de su estabilidad térmica y mecánica.
The recent discovery of superconductivity on MgB2 at
temperatures below 40 K in 2001, has opened a new
field of superconducting materials with critical
temperatures comprised between the existing low
temperature
(LTS)
and
high
temperature
superconductors (HTS), for their use in applications at
20-25 K, easily reachable with cryocoolers. The
material novelty, the low cost of the rough materials,
its low anisotropy and the promising performances
already achieved, have aroused considerable interest
in its study from a scientific and technological point of
view.
The Applied Superconductivity Group at the ICMA is
currently working on the development, optimisation
and analysis of composite metal/MgB2 wires and
tapes using the Powder in Tube (PIT) method, using
different metallic sheath, such as Cu and Ni. PIT
technology, widely searched at laboratory scale and
fully developed at industrial scale in recent years for
the fabrication of Ag/PbBi-2223 tapes, has been
proven to be useful in the conformation of MgB2
composites. In this technique, fully reacted powders
of MgB2 or unreacted Mg+2B powders are packed
inside metallic tubes, which are subsequently drawn
to wires or/and rolled to tapes. Finally, an additional
heat treatment in the absence of oxygen is used to
sinter or react the precursor powders. It is clear that
the choice of the metallic sheath is crucial as it should
be able to provide mechanical, thermal and electrical
stability to the superconductor without deteriorating
their properties.
The research is currently focused on the improvement
of these materials in two main aspects: to increase
the magnetic flux pinning, in order to enlarge the
useful field range of this material; and to improve the
thermal and mechanical stability.
Publicaciones:
E. Martínez, L. A. Angurel, R. Navarro. Study of Ag and Cu/MgB2 powder-in-tube composite wires fabricated by in
situ reaction at low temperatures. Supercond. Sci. Technol. 2002, 15, 1043-1047.
E. Martínez, L. A. Angurel, R. Navarro, A. Millán, C. Rillo, M. Artigas. Study of MgB2 powders and Cu/MgB2 powderin- tube composite wires with Zn addition. IEEE T. Appl. Supercon. 2003, 13, 3210-3213.
Proyectos:
Fabricación y caracterización de cintas compuestas de BSCCO y plata para aplicaciones eléctricas de potencia.
(MAT99-1028).
Fabricación de materiales superconductores para aplicaciones eléctricas de potencia y análisis de los procesos de
degradación en servicio. (MAT2002-04121-C03-02).
Miembros del ICMA que participan en esta línea:
R. Navarro, E. Martínez, L. A. Angurel, A. Millán.
128
Especiación del hierro biológico
Speciation of biological iron
La investigación se centra en la monitorización por
métodos no convencionales, en particular mediante
detección magnética, de los cambios producidos en
la especiación del hierro en medios biológicos. La
presencia del hierro, en forma de pequeños
agregados
inorgánicos,
en
algunos
tejidos,
especialmente en individuos con sobrecarga de hierro
y fundamentalmente en
sus especies de
almacenamiento,
ofrece
un
comportamiento
magnético detectable mediante las técnicas
modernas de alta sensibilidad. Este comportamiento
es correlacionable con su estructura a escala
nanoscópica y permite obtener nuevos datos acerca
del metabolismo del hierro. El estudio de ejemplos de
fármacos antianémicos, con los mismos criterios,
permite asimismo conocerlos mejor y complementar
los conocimientos existentes en cuanto a su eficacia.
El trabajo se realiza sobre modelos con ratas,
mediante
administración
de
fármacos
y
caracterización post mortem de los tejidos
correspondientes. La determinación del contenido de
hierro en cada individuo se realiza por métodos
convencionales
y
su
especiación,
objetivo
fundamental del proyecto, se acomete a partir de
caracterización magnética, tanto estática como
dinámica, mediante técnica SQUID y de microscopia
electrónica de transmisión.
Los resultados obtenidos deben ser de gran utilidad
tanto en farmacología como en el conocimiento más
profundo de patologías relacionadas con el
metabolismo del hierro.
The research is focused on monitoring, by non
conventional methods, in particular by magnetic
detection, the changes of the iron speciation in
biological media. The presence of iron, as very small
inorganic clusters in some tissues, especially in
individuals with iron overload and primarily in the iron
storage organs, give rise to a magnetic behaviour
which is detectable by high sensitivity modern
techniques. This behaviour is correlatable with its
structure at nanoscopic scale and allows the
obtention of new data on the iron metabolism. The
study of examples of antianaemic drugs, with the
same criteria, allows in addition their better
understanding, improving the knowledge about their
efficiency.
The work takes place with rat models, by means
administering drugs and by characterising post
mortem the corresponding tissues. The determination
of the iron content in each individual is carried out by
conventional methods and its speciation, central
objective of the project, is assessed by magnetic
characterisation, either statical and dynamical, by
SQUID techniques and transmission electron
microscopy.
The obtained results should be of much interest either
in pharmacology and in the deeper understanding of
pathologies related with the iron metabolism.
Publicaciones
F. J. Lázaro, A. Larrea, A. R. Abadía, M. S. Romero. Magnetic study of iron sorbitol. J. Magn. Magn. Mater. 2002,
250, 256-259.
F. J. Lázaro, A. Larrea, A. R. Abadía. Magnetostructural study of iron dextran. J. Magn. Magn. Mater. 2003, 257,
346-354.
Proyectos
Métodos de análisis de tipo magnético para la determinación de formas submicrométricas de presencia de hierro en
régimen diluido, y su aplicación a la caracterización de tamices moleculares, fármacos y sistemas biológicos
(PB1998-1606).
Especiación del hierro biológico (DGA, Grupo emergente).
Miembros del ICMA que participan en esta línea:
F. J. Lázaro, A. Larrea
129
Aplicaciones de la aleación de memoria de forma
NiTi en Medicina.
Development of medical devices based on NiTi
shape memory alloy.
De entre las diferentes aleaciones de memoria de
forma, la aleación equiatómica de níquel-titanio
presenta notables características tanto desde le
punto de vista de la transformación austenitamartensita como de las propiedades termomecánicas que de ella se derivan: memoria de forma
de un camino, de dos caminos, superelasticidad y
anelasticidad. La combinación de estas propiedades
junto a su biocompatibilidad ha permitido su
aplicación tanto al campo de la industria como al de
la medicina.
En el aspecto básico del material, la investigación se
centra en los métodos de entrenamiento para obtener
memoria de forma de dos caminos con la mayor
eficacia, en la influencia sobre las temperaturas de
transformación y en el envejecimiento por fatiga
térmica.
El grupo también investiga en la modelización del
material mediante ecuaciones constitutivas que den
cuenta de los fenómenos termomecánicos, como
primer paso en el diseño de dispositivos. Las
aplicaciones en las que se trabaja son stents para
colon, ferulajes para articulaciones y anclajes óseos.
Los prototipos se han fabricado mediante tecnología
de corte por láser, deformaciones en fase martensita
y tratamientos térmicos para la fijación de formas.
Otra línea más reciente es la modificación superficial
del NiTi mediante implantación iónica para mejorar su
biocompatibilidad. Se utilizan técnicas de corrosión
en continua y espectroscopia de impedancias.
Amongt the shape memory alloy (SMA) binary NiTi
alloys
present
noticeable
transformation
characterisitics,
mechanical
properties
and
biocompatibility behavior. Applications of these alloys
have become widespread for different devices for use
in industry and medicine. More of these applications
are based on the one-way memory effect,
superelasticity, and anelasticity.
The research trie to depth in the knowledge of the
thermal-mechanical behavior, in particular the training
methods to achieve two-way shape memory
deformation ( TWSME), its dependence on the initial
strain, the influence on thermal parameters of the
austenite-martensite transition ans its stability.
The group also research in the field of modelling the
material by means of constitutive equations in order to
design NiTi devices using finite elements simulations.
By other hand, we used cutting laser beam
technology, as method to obtain initial structures and
on the thermal-mechanical treatments to develop
work configurations. The applications in medicine of
the former know-how are stents for colon, splints for
finger joint and suture anchors.
Publicaciones
R. Lahoz, L. Gracia-Villa, J. A. Puértolas. Training of the two-way shape memory effect by bending in NiTi Alloys. J.
Engineering Materials an. 2002, 124, 397-401.
Proyectos
Diseño y fabricación de stents metálicos con NiTi. (FD97-2069-C02-02).
Miembros del ICMA que participan en esta línea:
J. A. Puértolas.
130
Mejora del polietileno de ultra alto peso molecular
(PEUAPM) utilizado en prótesis articulares.
Improvement of ultra high molecular weigh
polyethylene used in total joint replacements.
El PEUAPM es el material débil del par metalpolímero o cerámica-polímero en las actuales prótesis
de cadera y rodilla. El método de disminuir el
desgaste y alargar la vida ¨in vivo¨ de la prótesis es la
reticulación de las cadenas por irradiación. Sin
embargo, se ha observado que la radiación gamma
produce a largo plazo una fragilización del material en
zonas sub-superficiales que pudiera estar relacionada
con los fallos prematuros del material. Este proceso
aparece asociado a una degradación oxidativa como
consecuencia de los radicales que se producen
durante la escisión de las cadenas en presencia de
oxígeno. La alternativa actual pasa por una
irradiación con electrones, junto a pre o post
procesos térmicos
La investigación del grupo se centra en el estudio de
la microestrucutura mediante TEM para conocer la
influencia de los procesos en la distribución lamelar y
cristalinidad del material, y como se manifiestan estos
cambios en la fractografía de muestras ensayadas a
tracción. Se han analizado polietilenos de prótesis
irradiadas con gamma y un envejecimiento natural de
más cinco años y de polietilenos obtenidos a partir de
prótesis retiradas. También se ha evaluado desde un
punto de vista microscópico los procesos de
envejecimiento
acelerado
térmicamente
para
reproducir el envejecimiento natural.
Si bien la reticulación mediante electrones mejora el
desgaste en cadera, no parece claro este avance en
rodilla debido a que la fatiga juega un papel
determinante. Por esta razón, se ha estudiado la
resistencia a fatiga de polietilenos irradiados a
diferentes dosis con y sin el tratamiento térmico
posterior.
The most widely accepted configuration of total joint
replacement is based on metallic or ceramic
components articulating against UHMWPE. During
the last decades, gamma irrradiaition in air has been
the most widespread sterilization for crsoolinking the
polymer and in consequence to obtain an
improvement in the wear. However, in the long term
there are defects due to oxidation caused by
remaining free radicals after irradiaition, so new
crosslinking patways have been analysed Electron
beam irradiation with prior or further thermal
treatments is the new sterilization and crosslinking
alternative.
The research of the group is focused on the in fluence
of these processes on the microstructure, such as the
lamellar distribution, with the use of TEM, and the
fracture surface behaviour after uniaxial tenile tension
by SEM. We have compared samples from protheses
with shelf storage time longer than five years with
sampled from retired protheses after failure, for
testing the presence of the oxidation defects.
Therefore, we have assesed from a microstrural
aspect, if the ASTM protocols for accelerated thermal
aging after gamma irradiaition in air, matching the
natural aging.
Althoug the electron beam irradiaition is followed by
significant improvement in UHMWPE wear resistance,
the behaviour in the joint knee replacement is less
evident, due to the high contribution of other wear
modes as the fatigue wear. We have studied the
fatigue resistance of UHMWPE after electron beam
irradiation at different doses with or without a
remelting process as a further thermal treatment.
Publicaciones
J. A. Puértolas, A. Larrea, E. Gómez-Barrena. Fracture behaviour of UHMWPE in non-implanted, shelf-aged knee
prostheses after gamma irradiation in air. Biomaterials 2002, 22, 2107-2114.
Proyectos
Mejora del polietileno de interposición en prótesis totales articulares y evaluación de mecanismos de fallo.
(MAT2000-1278).
Miembros del ICMA que participan en esta línea:
J. A. Puértolas.
131
Propiedades
mecánicas
de
materiales
compuestos polimero-nanotubos de carbono
obtenidos mediante diferentes procesos
Mechanical properties of carbon nanotube
polymer-matrix composite materials obtained by
different processes
El modulo de Young axial de los nanotubos de
carbono se ha estimado en 1 TPa y su resistencia a
tracción en 200 GPa. Estas estructuras son
aproximadamente 100 veces más resistentes que el
acero y seis veces menos densas. Son estables
térmicamente hasta 2800ºC en vacío y sus
conductividades térmica y eléctrica son varias veces
más altas que el cobre.
Por lo tanto, los nanotubos de carbono parecen ser
materiales ideales como refuerzo de polímeros por
sus propiedades físicas, mecánicas, eléctricas y
térmicas, superiores a las fibras actuales. Esta nueva
generación
de
materiales
tiene
numerosas
aplicaciones potenciales, tales como músculos
artificiales,
componentes
ultraligeros
para
aeronáutica y espacio... Sin embargo, aún existen
barreras tales como la dispersión, la adhesión
nanotubo-matríz, alineamiento y la optimización del
sistema nanotubo-polímero.
Estamos trabajando en la purificación de estos
materiales, eliminando los catalizadores metálicos,
nanopartículas de grafito o carbón desordenado así
como en la mejora de la dispersión mediante técnicas
ultrasónicas. También estamos trabajando en la
mejora de la adhesión entre los nanotubos de
carbono y la matríz polimérica para generar una
correcta tensión de transmisión entre ambos
sistemas, mediante técnicas de plasma. Finalmente,
los nanotubos de carbono deben estar alineados para
optimizar las propiedades de estos sistemas
reforzantes, línea en la que tambien estamos
trabajando mediante
la aplicación de campos
magnéticos.
The Young modulus of carbon nanotubes in the axial
direction has been estimated in 1 TPa and its tensile
strength in 200 GPa. These structures are about one
hundred stronger than steel and their density is about
six times lower. Carbon nanotubes are thermally
stable up to 2800 ºC in vacuum conditions and their
thermal and electrical conductivities are several times
higher than copper.
Therefore, carbon nanotubes seem to be the right
material for reinforcing polymeric matrices since they
exhibit superior physical, mechanical, electrical and
thermal properties than fibres used nowadays. This
new generation of nanocomposites would be ideal for
a large variety of applications such as artificial
muscles, ultra-light space and aeronautic structural
components. However, there are still a number of
barriers to overcome for these materials to be used as
reinforced systems in composite materials. They are
related to dispersion, adhesion, alignment and
optimisation of the nanocomposite structures formed
by the carbon nanotubes and the polymer where they
are embedded.
We are working in the purification and dispersion of
the nanotubes into the matrix by means of ultrasound
techniques. Also, the strong adhesion between the
carbon nanotubes and the polymeric matrix, is
another goal we are achieving by means of plasma
procedures. Finally, the carbon nanotubes must be
aligned to optimise the properties of these reinforcing
systems, we are applying magnetic field techniques to
orient the nanotubes in the right directions.
Publicaciones
P. Laborde-Lahoz, W. Maser, T. Martínez, A. Benito, T. Seeger, P. Cano, R. Guzman de Villoria, A. Miravete.
Mechanical characterization of carbon nanotube composite materials. Mechanics of Advanced Materials and
Structures. TNT weekly, TNTW Issue 2003, 12.
Proyectos
Low cost compact solar heaters made of plastic materials and composites (COMPACT) (EU CRAFT-1999-72476).
Low risk and totally recyclable structural buildings (SAFEFLOOR) (EU EVK5-CT-2000-00552).
Miembros del ICMA que participan en esta línea:
A. Miravete, R. Guzmán, N. Tolosana
132
Modelizacion numérica de nuevos materiales
compuestos de matríz orgánica incluyendo
preformas textiles trenzadas
La utilización de materiales compuestos ha
aumentado rápidamente en los últimos tiempos.
Muchos sectores han considerado esta opción, como
la óptima debido a sus excelentes prestaciones,
elevadas rigidez y resistencia, alta absorción de
energía especifica, resistencia a la fatiga y a la
corrosión.
La inclusión de preformas trenzadas en 2D y 3D
permite la generación de complejas geometrías con
una
arquitectura
de
hilo
tridimensional,
específicamente trazada para satisfacer exigentes
criterios de comportamiento, más elevados que para
metales y materiales compuestos laminados.
Esta línea de investigación está centrada en el
desarrollo de tecnologías eficientes en coste para
llevar a cabo componentes de geometría compleja y
altas prestaciones. Para ello, es necesario llevar a
cabo un proceso de caracterización mecánica
completa y un programa de optimización con objeto
de realizar una evaluación completa de esta
tecnología.
Una caracterización mecánica completa a unos
niveles meso- y macro-mecánicos constituye un
importante criterio a considerar en la evaluación de la
tecnología. A partir de ahí, es posible identificar
nuevas aplicaciones, determinar cual es el mejor
material y la mejor configuración de la preforma. La
caracterización se lleva a cabo siguiendo tres
diferentes metodologías:
−
−
−
Un programa de ensayos.
Modelos de EF meso-mecánicos.
Un modelo analítico de material.
Numerical modelling of new composite materials
including braided textile preforms
The utilization of composite materials has grown
rapidly in the last years. Many sectors have
considered them the best choice in many cases due
to their outstanding performance, combining high
stiffness and strength at low density, high-specific
energy absorption, excellent fatigue performance and
high corrosion resistance.
Moreover, advanced composites reinforced with 2D
and 3D braided fabrics allows complex textile
preforms to be produced with a 3D yarn architecture,
specifically designed to satisfy high designrequirements with performances clearly superior to
that of conventional metals or composites.
This line is focused on the development of costeffective braiding technologies for complex shaped
high-performance composite products, including
design, process and simulation analyses. For this, a
complete
mechanical
characterization
and
optimisation program was essential in order to
perform a scope evaluation of the braiding
technology.
A complete mechanical characterization in meso and
macro mechanical levels will finally constitute an
important criterion to be considered in the
technological evaluation. Through this, is possible to
detect new applications, determine the best material
and preform configuration. The braided composites
characterization has been carried out by means of
three different methodologies:
−
−
−
An experimental testing program.
Meso-mechanic FE models.
An analytic material model.
Publicaciones
A. Miravete, M. A. Jiménez . Application of the finite element method to prediction of onset of delamination growth.
Appli. Mech. Rev. 2002, 55- 2, 89-106.
D. Revuelta, A. Miravete. Fatigue damage on composite materials. Int. Appli. Mech. 2002, 38, 121-134.
Proyectos
Development of a cost-effective 3-D braiding manufacturing process for complex shaped high-performance
composite products (COBRAID) (EU G1RD-CT00-00380).
Technologies for carbon fibre reinforced modular automotive body structures (TECABS) (EU G3RD-CT-2000-00102).
Miembros del ICMA que participan en esta línea:
A. Miravete, J. Cuartero, L. Castejón.
133
Materiales dendrímeros funcionales
Functional dendrimer materials
Los dendrímeros son, en general, polímeros
globulares, altamente ramificados, de forma
tridimensional, tamaño y peso molecular bien
definidos que se construyen por procedimientos
iterativos o por pasos. La modificación estructural de
dendrímeros con unidades anisótropas (mesógenas o
promesógenas) da lugar a materiales polímeros con
propiedades de cristal líquido, en los que la relación
estructura-actividad mesógena puede establecerse
de un modo excepcionalmente racional. En estos
materiales, las diversas unidades submoleculares se
ven forzadas a situarse en posiciones determinadas,
provocando importantes modificaciones estéricas,
con el fin de conseguir las estructuras más estables.
De este modo, los dendrímeros muestran una gran
variedad de geometrías macromoleculares que
proporcionan organizaciones originales en algunos
casos y/o propiedades nuevas y de gran interés en
otros. Nuestro grupo trabaja en la síntesis y
caracterización de dendrímeros cristal líquido,
utilizando gran variedad de estructuras tanto en las
unidades (pro)mesógenas como en la porción
dendrímera. La caracterización de los dendrímeros
se realiza por microscopía óptica, DSC, TGA-DTA,
GPC y difracción de rayos X. Asimismo, los
materiales dendriméricos se procesan y caracterizan,
en ocasiones, como películas delgadas. El estudio
completo de los materiales preparados nos permite
establecer modelos que explican la relación
estructura-propiedades
de
los
mismos.
Recientemente, nuestro grupo ha comenzado a
investigar en una nueva línea dedicada a la
preparación
de
nanopartículas
metálicas
encapsuladas en matrices dendriméricas, con el fin
de estudiar, entre otras, sus propiedades magnéticas.
Dendrimers are, in general, globular polymers, highly
branched, tridimensional-shaped, with web-defined
size and molecular weight, which are built by iterative
procedures. The structural modification of dendrimers
with anisotropic units (mesogenic or promesogenic)
gives rise to polymer materials, in which the structuremesogenic activity relationship can be satisfactorily
rationalised. In these covalent materials, the
molecules are forced to adopt very constrained and
regular structures and consequently, the different
molecular parts tend to adopt the most favourable
positions in order to obtain the most stable structure.
In this way, dendrimers show a wide variety of
macromolecular structures that give rise to original
organisations in some cases and/or new and
interesting properties in other. Our group is involved
in the synthesis and characterisation of liquid crystal
dendrimers, using a variety of structures both for the
(pro)mesogenic units and for the dendrimer moiety
itself. The characterisation of the dendrimers is
carried out by a number of techniques, such as optical
microscopy, DSC, TGA-DTA, GPC and X-ray
diffraction. Moreover, in some cases, the dendrimeric
materials are processed and characterised as
samples consisting in thin films. The study of the
materials allows us to establish models to explain
their structure-properties relationship. Recently, our
group has started a new research line: the
preparation
of
dendrimer-encapsulated
metal
nanoparticles, in order to study their magnetic
properties.
Publicaciones
B. Donnio, J. Barberá, R. Giménez, D. Guillon, M. Marcos, J. L. Serrano. Controlled molecular conformation and
morphology in poly(amidoamine) (PAMAM) and poly(propyleneimine)(DAB) dendrimers. Macromolecules 2002, 35,
370-381.
J. M. Rueff, J. Barberá, B. Donnio, D. Guillon, M. Marcos, J. L. Serrano. Lamellar to columnar mesophase evolution
in a series of PAMAM liquid–crystalline co-dendrimers. Macromolecules 2003, 36, 8368-8375.
M. Marcos, A. Omenat, J. L. Serrano. Structure-mesomorphism relationship in terminally functionalised liquid crystal
dendrimers. C.R. Chim. 2003, 6, 947-957.
Proyectos
Super molecular liquid crystal dendrimers. UE (RTN-1999-00311).
Polímeros funcionales para aplicaciones en óptica lineal y no lineal. CICYT (MAT2002-04118-C02-01).
Miembros del ICMA que participan en esta línea:
M. Marcos, J. Barberá, A. Omenat , J. L. Serrano, R. Martín, M. McKenna.
134
Polímeros funcionales para aplicaciones ópticas y
funcionales
Functional polymers for optical and mechanical
applications
La capacidad auto-organizativa de los cristales
líquidos puede ser aprovechada en polímeros para
desarrollar materiales funcionales con propiedades
anisótropas. En nuestro laboratorio se está
trabajando en diversas líneas de investigación sobre
la síntesis, procesado y estudio de polímeros cristal
líquido (LCPs) para dos tipos básicos de
aplicaciones: ópticas y mecánicas. Así, la
incorporación de grupos fotocrómicos (principalmente
azobencenos) y el fotocontrol de sus movimientos o
isomerización, permite acceder, por ejemplo, a
dispositivos
de
almacenamiento
óptico
de
información, holografía, guiado de luz o para óptica
no lineal. En este tipo de materiales es también
posible la inducción de estructuras supramoleculares
quirales mediante iluminación con luz en películas de
polímeros aquirales. Otra línea de trabajo se centra
en el procesado y estudio de películas con
anisotropía molecular controlada para luminiscencia
polarizada a partir de luminóforos cristales líquidos
fotorreactivos, o de polímeros que incorporan
fotocrómicos cinamato como orientadores del
luminóforo. Una última línea de trabajo, en fibras de
LCPs de cadena principal procesados en mesofase,
con lo que conlleva un reforzamiento de las
propiedades mecánicas en la dirección de orientación
molecular.
The self-organizing ability of liquid crystals polymers
gives rise to functional materials having anisotropic
properties. In our laboratories, we are working on
differente topics related with the synthesis, processing
and study of liquid crystal polymers (LCPs) for optical
or mechanical applications. Thus, the incorporation of
photochromic groups (azobenzenes) on LCPs and the
photocontrol of their movements or isomerizations
allow us to design optical devices for optical or
holographic storage, waveguiding or non-linear optics.
Furthermore, photoinduced chirality can be also
achieved in these achiral materials by illumination
with circular polarized light. Other topic concerns the
processing of anisotropic polymeric films having
polarized luminescence, which are processed from
photoreactive liquid crystal luminophores or polymers
which incorporate photochormic cinnamate groups for
orienting the luminophores. Finally, another research
topic is devoted to the processing of main chain LCPs
into fibers. Processig is carried out in the mesophase
wich leads to an improvement of mechanical
properties along the molecular orientation.
Publicaciones
L. Oriol, M. Piñol, J. L. Serrano, R. M. Tejedor. Síntesis, characterization and photoreactivity of liquid crystalline
cinnamates. J. Photoch. Photobio. A., 2003, 155, 37-45.
J. M. Adell, M. P. Alonso, J. Barberá, L. Oriol, M. Piñol, J. L. Serrano. Structural modifications and fibre processing of
hydroxy-functionalised mesogenic polyazomethines. Polymer, 2003, 44, 7829-7841.
Proyectos
Polímeros funcionales para aplicaciones en óptica lineal y óptica no líneal (proyecto coordinado con el Dpto. de
Física de la Materia Condensada). (MAT2002-04118-C02-01).
Miembros del ICMA que participan en esta línea:
L. Oriol, M. Piñol, J. Barberá, J. L. Serrano, R. Tejedor, A. Viñuales, L. Silvino, P. Forcén.
135
Organizaciones supramoleculares basadas en
cristales líquidos para aplicaciones en electrónica
molecular
Supramolecular organizations based on liquid
crsytals for molecular electronics applications
Los cristales líquidos ofrecen un particular control
sobre parámetros como orientación, geometría y
simetría de la organización supramolecular. Tomando
como base esta particularidad, nuestro grupo se ha
planteado la utilización de los cristales líquidos, como
herramientas para la preparación y control de
organizaciones supramoleculares con orden polar,
fundamentalmente no-centrosimétricas, que permitan
la manifestación de propiedades ópticas no lineales
y/o
comportamientos
ferro-,
antiferro-,
o
piroeléctricos. Para ello, se está trabajando en dos
tipos de organizaciones mesomorfas. Por un lado,
cristales líquidos que den lugar a mesofases
columnares, con una arquitectura helicoidal quiral.
Este tipo de arquitecturas moleculares, además de
ofrecer orden polar, se prevé permitirán obtener
materiales con propiedades de luminiscencia
circularmente polarizada. Asimismo, se plantea la
utilización de cristales liquidos organizados en
columnas helicoidales quirales como moldes para la
generación de estructuras con poros helicoidales. El
segundo tipo de estructuras en que se está
investigando se basa en moléculas en forma de V, los
denominados compuestos banana. Estas estructuras,
por su particular geometría, permiten obtener
empaquetamientos mesomorfos distintos a los
descritos clásicamente, entre los cuales, y debido a la
restricción
de
giros
moleculares,
algunos
proporcionan ordenaciones altamente polares y no
centrosimétricas incluso en ausencia de quiralidad.
Para el control de ambos tipos de estructuras se
plantea utilizar un diseño molecular basado no solo
en interacciones covalentes sino también en otras
interacciones más dinámicas y direccionales como el
enlace de hidrógeno.
Liquid crystals offer a particular control on parameters
such as orientation, geometry and symmetry of the
supramolecular organization. On the basis of this
characteristic, our research is aimed at using liquid
crystals, as a tool to prepare and control
supramolecular organizations with polar order, noncentrosymmetric, that enable the appearance of ferro,
antiferro-, or pyroelectric properties. Or group is
working on two types of mesomorphic organization.
On one hand, mesogenic molecules that self-organize
into columnar mesophases with chiral helical
architecture. These structures allow envisaging the
achievement of materials displaying circularly
polarized luminescence. Likewise we are considering
employing chiral helical columnar liquid crystals as
templates to build up structures with helical porous. A
different type of liquid crystalline structures is based
on V-shaped molecules. The so-called ”banana”
compounds. These structures, due to their bent
geometry, allow mesophases that provide strong
polar arrangements, some of them in a noncentrosymmetric way, even for achiral structures.
In order to control all these types of architecture we
are employing a molecule design based not only in
covalent interactions but also in weaker interactions
such as the dynamic and directional hydrogenbonding.
Publicaciones
J. Barberá, E. Cavero, M. Lehmann, J. L. Serrano, T. Sierra, J. T. Vázquez. Supramolecular helical stacking of
metallomesogens derived from enantiopure and racemic polycatenar oxazolines. J. Am. Chem. Soc. 2003, 125,
4527-4533.
J. L. Serrano, T. Sierra. Helical supramolecular organizations from metal-organic liquid crystals. Coord. Chem. Rev.,
2003, 242, 73-85.
C. Artal, M. B. Ros, J. L. Serrano, N. Pereda, J. Etxebarria, C. L. Folcia, J. Ortega. SHG characterization of different
polar materials obtained by in situ photopolymerization. Macromolecules, 2001, 34, 4244-4255.
C. Ortega, L. Folcia, J. Etxebarria, N. Gimeno, M. B. Ros. Interpretation of unusual textures in the B2 phase of a
liquid crystal composed of bent-core molecules. Phys. Rev. E., 2003, 68, 11707.
Proyectos:
Materiales moleculares cristal líquido para aplicaciones en electrónica molecular. (MAT2003-07806-CO2-01).
Miembros del ICMA que participan en esta línea.
B. Ros, T. Sierra, J. L. Serrano, R. Giménez, S. Uriel, M. Savirón, N. Gimeno, R. Piñol, L. Puig, E. Cavero, I. Pintre,
F. Vera.
136
Sistemas push-pull con propiedades ópticas no
lineales de segundo orden
Push-pull systems with second order nonlinear
optical properties
Los sistemas push-pull de estructura general D-π-A,
siendo D una unidad dadora de electrones y A una
unidad aceptora de electrones, conectadas a través
de un espaciador conjugado (π), son entidades
dipolares que muestran propiedades ópticas no
lineales de segundo orden, ya que poseen primeras
hiperpolarizabilidades moleculares elevadas. Nuestro
grupo trabaja en la preparación y estudio de estos
sistemas dipolares, utilizando como unidad D
derivados de tetratiafulvaleno o fragmentos
proaromáticos relacionados, tales como ditiafulvenos.
Por su parte, el fragmento aceptor puede ser un
grupo aromático, neutro o cargado o, de nuevo, un
grupo proaromático. La modificación de la naturaleza
de los grupos terminales y la modulación de la
longitud y naturaleza del espaciador permiten
optimizar la transferencia de carga intramolecular y,
por tanto, la respuesta óptica no lineal de segundo
orden. Las propiedades ópticas lineales y no lineales
de las moléculas sintetizadas se han evaluado tanto
teórica como experimentalmente.
Push-pull systems of general structure D-π-A, where
an electron donor unit (D) and an electron acceptor
unit (A) are linked through a conjugated spacer (π),
are dipolar entities endowed with second-order
nonlinear optical properties, thanks to their high first
molecular hyperpolarizabilities. Our group is involved
in the synthesis and study of such dipolar systems,
where D is either a tetrathiafulvalene derivative or a
closely related proaromatic moiety, such as
dithiafulvene. The acceptor group, in turn, can be a
charged or non-charged aromatic group or a
proaromatic fragment too. The nature of the end
groups, and the length and the nature of the π spacer
can be modulated with a view to maximize the
intramolecular charge-transfer and, therefore, the
second-order nonlinear optical response. The linear
and nonlinear optical properties of the synthesized
molecules are evaluated both experimentally and
theoretically.
Publicaciones
R. Andreu, J. Garín, J. Orduna, G. J. Ashwell, M. A. Amiri, R. Hamilton. (E)-4-[2(bis(octadecylsulfanyl)tetrathiafulvalenyl)ethenyl]-1-methylpyridinium iodide: synthesis and characterisation of its
Langmuir-Blodgett films. Thin Solid Films 2002, 408, 236-239.
M. Otero, M. A. Herranz, C. Seoane, N. Martín, J. Garín, J. Orduna, R. Alcalá, B. Villacampa. Synthesis and
properties of push-pull chromophores for second-order nonlinear optics derived from π-extended tetrathiafulvalenes
(TTFs). Tetrahedron 2002, 58, 7463-7475.
R. Andreu, J. Garín, J. Orduna, R. Alcalá, B. Villacampa. Novel NLO-phores with proaromatic donor and acceptor
groups. Org. Lett. 2003, 5, 3143-3146.
Proyectos
Síntesis, caracterización y propiedades ópticas no lineales de nuevos cromóforos de tipo merocianina.(P009/2001).
Dadores π-electrónicos y sistemas de transferencia de carga intramolecular basados en heterociclos proaromáticos.
(BQU2002-00219)
Sistemas de transferencia de carga intramolecular con propiedades ópticas no lineales de segundo y tercer orden.
(E39).
Miembros del ICMA que participan en esta línea:
J. Garín, J. Orduna, R. Andreu, L. Carraquer, C. López, M. Á. Cerdán, R. Alcalá, B. Villacampa.
137
Dinámica de inestabilidades termomagnéticas en
superconductores de tipo II
Magnetothermal instabilities dynamics in type II
superconductors
La investigación de inestabilidades termomagnéticas
es un tema fundamental tanto para la comprensión de
las propiedades básicas de los superconductores tipo
II, como para su adecuada caracterización y en el
desarrollo de sus potenciales aplicaciones.
Desde 1967, las teorías fenomenológicas de
acoplamiento de los fenómenos térmicos y
magnéticos se han basado en ciertas hipótesis
simplificadoras, ampliamente aceptadas, pero el
amplio espectro de observaciones experimentales
existente todavía carece de una visión completa y
unificada. Se pretende avanzar en este conocimiento,
simulando la respuesta detallada del material en los
procesos de avalancha de flujo magnético
provocados por impulsos térmicos. Para obtener
predicciones más cercanas a los experimentos, se
van a incorporar a la teoría actual una serie de
mecanismos físicos: imanación de equilibrio, efectos
de tamaño finito, anisotropía en la corriente crítica,
inhomogeneidades y fenómenos de corte de flujo
magnético.
The investigation of magnetothermal instabilities has
been a main topic in the field of type-II
superconductors and their prospective technological
applications. Thus, a vast number of scientific
publications can be found on this subject for the
conventional hard superconductors, the high-Tc
superconducting oxides, and already for the recently
discovered
intermediate
temperature
superconductors. Phenomenological
theories, in
which the coupling of electromagnetic and thermal
phenomena is realized under various assumptions
have been extensively used for decades. However, a
full picture description of the rich experimental
scenario is still lacking. We attempt to cover as high
as possible a number of open questions by an
extended phenomenological approach. In particular,
we propose to simulate the detailed time-dependent
temperature and electric field profiles along the
process of a flux jump for superconductors with
various types of E(J) equations. The evolutionary
distribution of penetrating flux density will be
considered, so as to compare with magnetic
measurements. To the moment, merely partial
aspects of both topics have been covered. In order to
get closer to the structure of the available data, we
wish to incorporate a number of mechanisms to the
theory: critical state and flux creep regimes, samplesize effects, anisotropy and spatial inhomogeneities in
the sample parameters or excitation field.
Publicaciones:
A. Badía, C. López. Minimal model for the topology of the critical state in hard superconductors. Capítulo del libro
"New Developments in Superconductivity Research". New York: Nova Science Publishers, 2003. pp 209-23
A. Badía, C. López. Vector Magnetic Hysteresis of Hard Superconductors. Phys. Rev. B 2002, 65, 104514.
A. de la Cruz, A. Badía. Analytical Model for the Levitation Force between a Small Magnet and a Superconducting
Cylinder in the Critical State. Physica B 2002, 321, 356.
A. Badía, C. López. The Critical State in Type-II Superconductors with Cross-Flow Effects. J. Low Temp. Phys.
2003, 130, 129-153.
Proyectos:
Fabricación y caracterización de cintas compuestas de BSCCO y plata para aplicaciones eléctricas de potencia
(MAT99-1028).
Dinámica de inestabilidades termomagnéticas en superconductores de tipo II (proyecto de investigación de la
Universidad de Zaragoza, modalidad B).
Miembros del ICMA que participan en esta línea:
A. Badía
138
Propiedades electromagnéticas de sistemas con
constante dieléctrica modulada. Óptica atómica.
En la linea de propiedades electromagnéticas se
aborda
el
cálculo
de
las
propiedades
electromagnéticas
de
estructuras
dieléctricas
periódicas, de la pérdida de energía de partículas
cargadas cuando pasan cerca de estructuras
metálicas corrugadas y, sobre todo, de las
propiedades de transmisión óptica (tanto de la
cantidad de luz transmitida como de la distribución
angular de dicha luz) a través de sistemas metálicos
nanoestucturados. En este ultimo caso, estamos
extendiendo el estudio, tanto teórico como
experimental (en colaboraciones externas) al régimen
de microondas.
Muy recientemente, hemos empezado una línea de
investigación en óptica atómica, donde estamos
estudiando si los efectos que hemos descubierto en
ondas de luz tienen una contraparte en sistemas
atómicos a muy baja temperatura, donde el
comportamiento ondulatorio de los átomos es
fundamental. Si esto fuera así, tendríamos toda una
serie de dispositivos que nos permitirían el guiado,
focalización, alta transmisión, etc. de átomos.
Electromagnetic properties of systems with a
spatially modulated dielectric constant. Atom
Optics.
We are working on the theory of electromagnetic
properties of periodic dielectric structures, of the
energy loss of charged particles passing close to
corrugated metallic structures and, especially, on the
optical transmission properties (both the total amount
of light passing through and its angular distribution)
through nanostructured metallic systems. In this last
case, we are extending the study (in close
collaboration with experimentalists) to the microwave
regime.
Very recently, we have started to work on atom optics,
where we are analising whether the effects that we
have found for electromagnetic waves have a
counterpart in atomic systems at very low
temperature, where the wave-like behaviour of atoms
is of paramount importance. If this were the case, we
could have access to a series of devices that could
allow the guiding, focalization and high transmission
of atoms.
Publicaciones
F. J. García-Vidal, L. Martín-Moreno. Transmission and focusing of light in 1D periodically nanostructured metals.
Phys. Rev. B 2002, 66, 155412.
H. J. Lezec, A. Degiron, E. Devaux, R. A. Linke, L. Martín-Moreno, F. J. García-Vidal, T. W. Ebbesen. Beaming light
from a subwavelength aperture, Science 2002, 297, 820-822.
L. Martín-Moreno, F. J. García-Vidal, H. J. Lezec, A. Degiron, T. W. Ebbesen. Theory of highly directional emission
from single sub-wavelength apertures surrounded by surface corrugations. Phys. Rev. Lett. 2003, 90, 167401.
Proyectos
Cristales fotónicos y materia condensada blanda.
Acoplamiento luz-materia y fenómenos colectivos en nanoestructuras semi-conductoras. (MAT 2002-00139).
Miembros del ICMA que participan en esta línea:
L. Martín.
139
Modos intrínsecos localizados en redes
uniones Josephson y redes no lineales.
de
Intrinsic localized modes (or discrete breathers) in
Josephson junction arrays and non linear lattices.
Las redes de uniones Josephson son dispositivos
superconductores de estado sólido con numerosas
aplicaciones científicas y tecnológicas. En ellas, es
posible estudiar experimentalmente los avances
recientes de la física no lineal. Consecuencia de
estos trabajos son nuevas aplicaciones tecnológicas.
Desde su constitución, nuestro grupo ha trabajado en
el estudio teórico de circuitos superconductores
basados en uniones Josephson, tanto en aspectos
dinámicos como de equilibrio. Sin embargo, desde
finales de 1997 llevamos a cabo una estrecha
colaboración con el grupo experimental del Prof.
Terry P. Orlando del Departamento de Ingeniería
Eléctrica y Ciencias de la Computación del Instituto
Tecnológico de Massachussets (M.I.T.). En el marco
de esta colaboración estamos estudiando desde el
punto de vista teórico, de simulación y experimental,
la existencia y propiedades de los modos intrínsecos
localizados (también llamados "discrete breathers")
en distintas redes de uniones Josephson. También
estamos interesados en
explorar las posibles
aplicaciones tecnológicas de estos trabajos.
En el aspecto puramente teórico, hemos estudiado
los fenómenos de movilidad de breathers en redes
disipativas no lineales: modelo Frenkel-Kontorova y
en el modelo no lineal discreto de Schrödinger
(DNLS).
Josephson-junction based arrays are solid state
superconducting devices with many scientific and
technological applications. There, it is possible to
experimentally study the recent advances of nonlinear
physics. As a result of this work, new technological
applications can be explored. From its constitution,
our group has worked in the theoretical study of the
static and dynamics of superconducting circuits made
of Josephson junctions. However, from 1997 it carries
out a close collaboration with the experimental group
of Prof. Terry P. Orlando, in the Department of
Electrical Engineering and Computer Sciences at the
Massachussets Institute of Technology (M.I.T.).
Within the framework of this collaboration we are
studying
theoretically,
with
simulations
and
experimentally the existence and properties of
intrinsic localized modes (also called discrete
breathers) in different Josephson-junction arrays. We
are also exploring the possible technical applications
of our results.
On the pure theoretical side, we are also studying
mobility phenomena of discrete breathers in nonlinear dissipative lattices, like the Frenkel-Kontorova
model and the discrete non-linear Schrödinger
equation (DNLS).
Publicaciones:
J. J. Mazo. Discrete breathers in 2d Josephson-junction arrays. Phys. Rev. Lett. 2002, 89, 234101.
J. J. Mazo, T. P. Orlando. Discrete breathers in Josephson arrays. Chaos 2003, 13, 733-743.
P. J. Martínez, M. Meister, L. M. Floría, F. Falo. Dissipative discrete breathers: Periodic, quasiperiodic, chaotic and
mobile. Chaos 2003, 13, 610-623.
Proyectos:
Localización y transporte en sistemas discretos no lineales: Aplicación a circuitos superconductores y sistemas
biológicos. (PB98-1592).
Modos no lineales en redes clásicas y cuánticas de uniones Josephson. Programa hispano-norteamericano de
cooperación científica y tecnológica 2000.
Localisation by nonlinearity and spatial discreteness, and energy transfer, in crystals, biomolecules and Josephson
arrays. (HPRN-CT-1999-00163).
Teoría y simulación de sistemas complejos. (BFM2002-00113).
Miembros del ICMA que participan en esta línea:
F. Falo, L. M. Floría, J. Gómez-Gardeñes, J. J. Mazo, P. J. Martínez, M. Meister, D. Zueco.
140
Movimiento direccional de
fluxones en redes no lineales.
defectos
y
Directional motion of defects and fluxons in
non- linear lattices.
El problema del movimiento direccional de
partículas bajo la acción de fuerzas de media
nula (fuerzas puramente ac), ha sido
profusamente estudiado en los últimos años.
Nuestra contribución en este campo es doble.
Por una parte, hemos desarrollado un diseño
para la rectificación del movimiento de fluxones
en redes de uniones Josephson en forma de
anillo. Estas redes de escala mesoscópica
constituyen un excelente banco de pruebas para
el estudio de este efecto tanto en su variante
clásica como en la cuántica. El estudio
experimental en el límite clásico-cuántico ha
sido hecho recientemente en colaboración con
el grupo del Prof. T. P.Orlando en el M.I.T. En la
actualidad, estamos realizando un notable
esfuerzo de desarrollo de la teoría en el límite
cuántico, lo que permitirá una mejor
comprensión de los experimentos.
Por otra parte, hemos propuesto nuevos
mecanismos de transporte direccional en
sistemas fluctuantes basados no en la difusión
térmica, sino en la interacción entre partículas.
The problem of the directional motion of particles
under unbiased forces (pure ac forces) has been
widely studied in last years. Our contribution to
this field has a double side. On one side, we
have developed a novel design to achieve
rectification in the fluxon motion in ring-shaped
Josephson junction arrays. These arrays are an
excellent bench-work (in the mesoscopic scale)
to study the ratchet effect in an extended
system, both in the classical and the quantum
regimes. The experimental study, in the classical
to quantum crossover has been recently
performed by the group of Prof. T.P. Orlando in
M.I.T. At present, we are developing very fast
and powerful theoretical methods to study the
quantum limit. This study will help a better
understanding
of
the
recently
made
experiments.
On the other side, we have proposed a new
mechanism for directional transport in fluctuating
systems ("flashing ratchet"). This mechanism is
grounded not in thermal diffusion but in interparticle interaction.
Publicaciones:
F. Falo, P. J. Martínez, J. J. Mazo, T. P. Orlando, K. Segall, E. Trías. Fluxon ratchet potentials in
superconducting circuits. Appl. Phys. A 2002, 75, 263-269.
L. M. Floría, F. Falo, P. J. Martínez, J. J. Mazo. Transport of modulated phases by pumping. Europhys.
Lett. 2002, 60, 174-180.
J. L. García-Palacios. Solving quantum master equations in phase space by continued-fraction methods.
Europhys. Lett. 2004, 65, 735-741.
Proyectos:
Localización y transporte en sistemas discretos no lineales: Aplicación a circuitos superconductores y
sistemas biológicos. (PB98-1592).
Modos no lineales en redes clásicas y cuánticas de uniones Josephson. Programa hispanonorteamericano de cooperación científica y tecnológica 2000.
Localisation by Nonlinearity and Spatial Discreteness, and Energy Transfer, in Crystals, Biomolecules and
Josephson Arrays. (HPRN-CT-1999-00163).
Teoría y Simulación de Sistemas Complejos. (BFM2002-00113).
Miembros del ICMA que participan en esta línea:
S. Cuesta, F. Falo, L. M. Floría, J. L. García-Palacios, J. J. Mazo, P. J. Martínez, D. Zueco.
141
2.2.- Proyectos de Investigación
Research Grants
143
2.2.1.- Financiación Europea
European Funding
1. Advanced ultra-thin ceramic membranes for efficient industrial processes (CERMOX)
Código: DR5D-CT-2000-00351
Fuente de financiación: Unión Europea
Importe total: 60.000 euros
Investigador principal: Víctor Orera Clemente
2. AMORE. Advanced Magnetic Oxides for Responsive Engineering
Código: G5RD-CT-2000-00138
Fuente de financiación: Unión Europea
Importe total: 177.500 euros
Investigador principal: Manuel Ibarra García
3. COBRAID. Devolpment of a Cost-effective 3D-Braiding manufacturing process for
complex shaped high-perfomance composite products.
Código: G1RD-CT-2000-00380
Fuente de financiación: Unión Europea
Importe total: 230.000 euros
Investigador principal: Antonio Miravete de Marco
4. COMPOSIT. Thematic network
Código: G4RT-CT-2001-05054
Fuente de financiación: Unión Europea
Importe total: 55.000 euros
Investigador principal: Antonio Miravete de Marco
5. High field infraestructure cooperative network
Código: NET-HPRI-CT/99-40013
Fuente de financiación: Unión Europea
Importe total: 7.200 euros
Investigador principal: Agustín del Moral Gámiz
6. Integral training and research in homogeneous catalisis by organometallic compounds
Código: MPMT-CT-2000-00200
Fuente de financiación: Unión Europea
Importe total: 240.000 euros
Investigador principal: Luis Oro Giral
7. Localisation by nonlinearity and spatial discreteness and energy transfer in crystals,
biomolecules and Josephson arrays
Código: HPRN-CT-199-00163
Fuente de financiación: Unión Europea
Importe total: 160.000 euros
Investigador principal: Luis Mario Floría Peralta
8. Low cost compact solar heaters made of plastic materials and composites (COMPACT)
Código:
Fuente de financiación: Unión Europea
Importe total: 245.700 euros
Investigador principal: Antonio Miravete de Marco
9. Low risk and totally recyclable structural buildings (SAFEFLOOR)
Código: EVK5-CT-2000-00552
Fuente de financiación: Unión Europea
Importe total: 141.743 euros
Investigador principal: Antonio Miravete de Marco
145
10. New mono and heterometallic azolates as new materials and new materials sources
Código: INTAS00-00469
Fuente de financiación: INTAS
Importe total:
Investigador principal: Luis Oro Giral
11. Phonon spectra, thermodynamic stability and phase transitions in perovskite-like
crystals
Código: RFBR97-10177
Fuente de financiación: INTAS
Importe total: 57.000 euros
Investigador principal: Ramón Burriel Lahoz
12. Spin, charge and orbital ordering in complex transition metal oxides: an integrated
synthesis and measurements approach (SCOOTMO)
Código: HPRN-CT-2002-00293
Fuente de financiación: Unión Europea
Importe total: 208.755 euros
Investigador principal: Clara I. Marquina García
13. SCENET2. European network for power application of superconductivity
Código: GCT2001-43047
Fuente de financiación: Unión Europea
Importe total:
Investigador principal: Rafael Navarro Linares
14. Supermolecular liquid crystal dendrimers
Código: HPRN-CT-2000-00016
Fuente de financiación: Unión Europea
Importe total: 180.000 euros
Investigador principal: José Luis Serrano Ostáriz
15. Surface plasmon photonics
Código: NMP4-CT-2003-505699
Fuente de financiación: Unión Europea
Importe total: 173.760 euros
Investigador principal: Luis Martín Moreno
16. Technologies for carbon fibre reinforced modular automotive body structures
(TECABS)
Código: G3RD-CT-2000-00102
Fuente de financiación: Unión Europea
Importe total: 144.800 euros
Investigador principal: Antonio Miravete de Marco
2.2.2.- Financiación Nacional
National Funding
1. Acoplamiento luz-materia y fenómenos
semiconductoras
Código: BFM2002-10883
Fuente de financiación: MCyT
Importe total: 11.176 euros
Investigador principal: Luis Martín Moreno
colectivos
en
nanoestructuras
2. Anisotropía magnética y magnetoelasticidad en capas finas de metales de transición
Código: HI2002-0167
146
Fuente de financiación: MCyT
Importe total: 10.400 euros
Investigador principal: Miguel Ciria Remacha
3. Aplicación de los métodos sin malla a la simulación numérica de procesos de
recubrimiento por láser
Código: DPI2002-01986
Fuente de financiación: MCyT
Importe total: 130.000 euros
Investigador principal: Germán de la Fuente Leis; Begoña Calvo Calzada
4. Activaciones de enlaces carbono-halógeno. Aplicaciones en catálisis homogénea
Código: 231-57
Fuente de financiación: MCyT
Importe total: 6.000 euros
Investigador principal: Montserrat Oliván Escó
5. Caracterización y aplicaciones de nuevos materiales nanoestructuras magnéticos
Código: MAT2002-04178-C04-03
Fuente de financiación: MCyT
Importe total: 159.855 euros
Investigador principal: Jesús Chaboy Nalda
6. Catálisis enantioselectiva por compuestos organometálicos
Código: BQU2003-01096
Fuente de financiación: MCyT
Importe total: 148.310 euros
Investigador principal: José Daniel Carmona Gascón
7. Catálisis homogénea por complejos organometálicos de metales de transición
Código: BQU2000-1170
Fuente de financiación: MCyT
Importe total: 316.373 euros
Investigador principal: Luis Oro Giral
8. Complejos con tiolatos polifuncionales. Preparación y estudio de sus aplicaciones
Código: BQU2002-04090-C02-01
Fuente de financiación: MCyT
Importe total: 189.259 euros
Investigador principal: Mariano Laguna Castrillo
9. Complejos de oro y plata: Preparación, estructura y potenciales aplicaciones
Código: BQU2001-2409-C02-01
Fuente de financiación: MCyT
Importe total: 144.243 euros
Investigador principal: Antonio Laguna Castrillo
10. Complejos hidruros de metales del grupo VIII como precursores de reacciones de
acoplamiento carbono-carbono
Código: PB-1591
Fuente de financiación: MCyT
Importe total: 138.233 euros
Investigador principal: Miguel Ángel Esteruelas Rodrigo
11. Complejos organometálicos polinucleares de rodio e iridio. Síntesis, estructura y
reactividad
Código: PB98-1598
Fuente de financiación: MCyT
Importe total: 83.961 euros
Investigador principal: María Pilar García Clemente
147
12. Complejos quirales inmovilizados con ligandos de tipo azabis (oxazolina) como
catalizadores de reacciones enantioselectivas
Código: HA2001-0096
Fuente de financiación: MCyT
Importe total: 9.556 euros
Investigador principal: José María Fraile Dolado
13. Compuestos de coordinación con ligandos polifuncionales: Efecto Jahn-Teller.
Estudio de la metodología de la cristalografía no rutinaria; informática no rutinaria
Código: PB98-1593
Fuente de financiación: MCyT
Importe total: 72.121 euros
Investigador principal: Lawrence Rocco Falvello
14. Compuestos organometálicos de metales de transición. Aproximaciones sintéticas a
especies de interés científico por su novedad estructural o de enlace o por sus
propiedades
Código: BQU2002-03997-C02-02
Fuente de financiación: MCyT
Importe total: 276.050 euros
Investigador principal: Juan Forniés Gracia
15. Corte y marcaje de baldosas cerámicas por láser
Código: 95-0351-OP
Fuente de financiación: MCyT
Importe total: 78.132 euros
Investigador principal: Germán de la Fuente Leis
16. Dadores pi-electrónicos y sistemas de transferencia de carga intramolecular basados
en heterociclos proaromáticos
Código: BQU2002-00219
Fuente de financiación: MCyT
Importe total: 93.644 euros
Investigador principal: Vicente Javier Garín Tercero
17. Dendrímeros carbosilanos funcionalizados con grupos hidrogenosulfuro como
soportes para catalizadores en reacciones de hidroformilación de olefinas
Código:
Fuente de financiación: MCyT
Importe total:
Investigador principal: Miguel Ángel Casado Lacabra
18. Desarrollo de aplicaciones catalíticas homogéneas promovidas por complejos de
metales de transición
Código: BQU2003-05412-C02-02
Fuente de financiación: MCyT
Importe total: 217.578 euros
Investigador principal: Luis Oro Giral
19. Determinación de la geometría de coordinación de iones de metales de transición
mediante análisis cuantitativo de los espectros de absorción de rayos X
Código: INFN2001
Fuente de financiación: MCyT
Importe total: 3.666 euros
Investigador principal: Joaquín García Ruíz
20. Dynamics of nonlinear networks: Localization and mobility
Código: HB1999-0104
Fuente de financiación: MCyT
148
Importe total: 7.754 euros
Investigador principal: Luis Mario Floria Peralta
21. Diseño, síntesis y estudio de compuestos de coordinación con ligandos
polifuncionales; cristalografía estructural no-rutinaria; informática cristalográfica
Código: BQU2002-00554
Fuente de financiación: MCyT
Importe total: 126.130 euros
Investigador principal: Lawrence Rocco Falvello
22. Estudio de las propiedades magnéticas y de transporte de los compuestos
magnetocalóricos TR5(SixGe1-x)4
Código: HP2002-0047
Fuente de financiación: MCyT
Importe total: 7.500 euros
Investigador principal: Pedro Algarabel Lafuente
23. Estudio de hilos cuánticos InAs/InP mediante espectroscopia EXAFS y DAFS con
radiación de sincrotrón
Código: HF2002-0078
Fuente de financiación: MCyT
Importe total: 10.200 euros
Investigador principal: Mª Grazia Proietti Cecconi
24. Estudio de óxidos de valencia mixta y nanoestructuras de semiconductores: Síntesis,
caracterización y aplicación de las espectroscopías de rayos X
Código: MAT2002-01221
Fuente de financiación: MCyT
Importe total: 283.096 euros
Investigador principal: Joaquín García Ruíz
25. Estudio de sistemas magnetorresistivos de alto interés en magnetoelectrónica
Código: MAT2002-04657
Fuente de financiación: MCyT
Importe total: 277.426 euros
Investigador principal: José María de Teresa Nogueras
26. Fabricación de materiales funcionales laminares mediante fusión por zonas asistida
por láser
Código: MAT2000-1495
Fuente de financiación: MCyT
Importe total: 188.334 euros
Investigador principal: Rosa Isabel Merino Rubio
27. Fabricación de materiales superconductores para aplicaciones eléctricas de potencia
y análisis de los procesos de degradación en servicio
Código: MAT2002-04121-C03-02
Fuente de financiación: MCyT
Importe total: 186.800 euros
Investigador principal: Luis Alberto Angurel Lambán
28. Fabricación de memorias no volátiles basadas en uniones túnel magnéticas
Código: HF2002-0115
Fuente de financiación: MCyT
Importe total: 10.200 euros
Investigador principal: José María de Teresa Nogueras
29. Fabricación y caracterización de cintas compuestas de BSCCO y plata para
aplicaciones eléctricas de potencia
Código: MAT99-1028
149
Fuente de financiación: MCyT
Importe total: 111.488 euros
Investigador principal: Rafael Navarro Linares
30. Heteroestructuras híbridas con aplicaciones en magnetoelectrónica
Código: MAT-2000-1290-C03-01
Fuente de financiación: MCyT
Importe total: 198.987 euros
Investigador principal: José Ignacio Arnaudas Pontaque
31. Imanes macroscópicos y nanoestructurados
Código: MAT2002-00166
Fuente de financiación: MCyT
Importe total: 306.312 euros
Investigador principal: Juan Bartolomé Sanjoaquín
32. Jornadas sobre el presente y futuro de la investigación en manganitas
Código: MAT2000-3144-E
Fuente de financiación: MCyT
Importe total: 4.508 euros
Investigador principal: Manuel Ibarra García
33. Localización y transporte en sistemas discretos no lineales: Aplicación a circuitos
superconductores y sistemas biológicos
Código: PB98-1592
Fuente de financiación: MCyT
Importe total: 42.071 euros
Investigador principal: Fernando Falo Forniés
34. Magnetismo y magnetoelasticidad en láminas delgadas y en sistemas masivos
fuertemente correlacionados
Código: MAT2003-00893
Fuente de financiación: MCyT
Importe total: 180.300 euros
Investigador principal: César de la Fuente del Rey
35. Magnetismo y radiación de sincrotrón (Acuerdo de colaboración CICYT-INFN)
Código: INFN2003
Fuente de financiación: MCyT
Importe total: 6.900 euros
Investigador principal: Jesús Chaboy Nalda
36. Materiales conductores iónicos para dispositivos electroquímicos de producción y
almacenamiento de energía
Código: MAT2001-3713-C04-02
Fuente de financiación: MCyT
Importe total: 71.881 euros
Investigador principal: María Luisa Sanjuán Álvarez
37. Materiales magnéticos avanzados: Síntesis, caracterización y aplicaciones
Código: MAT99-0667-C04-04
Fuente de financiación: MCyT
Importe total: 41.903 euros
Investigador principal: Jesús Chaboy Nalda
38. Materiales magnéticos moleculares: Materiales magnéticos multifuncionales y
moléculas biestables para la electrónica molecular
Código: MAT2001-3507-C02-02
Fuente de financiación: MCyT
Importe total: 169.125 euros
150
Investigador principal: Ramón Burriel Lahoz
39. Materiales magnéticos nanoestructurados y masivos con relevantes propiedades
para aplicaciones tecnológicas
Código: MAT1999-1063-C04-0
Fuente de financiación: MCyT
Importe total: 185.016 euros
Investigador principal: Manuel Ibarra García
40. Materiales masivos con relevantes propiedades magnetoelectrónicas
Código: MAT2000-1756
Fuente de financiación: MCyT
Importe total: 191.438 euros
Investigador principal: Clara I. Marquina García
41. Materiales moleculares magnéticos. Comportamiento magnético de materiales
moleculares y poliméricos
Código: MAT2000-1388-C03-03
Fuente de financiación: MCyT
Importe total: 70.006 euros
Investigador principal: Fernando Palacio Parada
42. Materiales para SOFC’s preparados mediante fusión zonal por láser
Código: MAT2003-01182
Fuente de financiación: MCyT
Importe total: 187.867 euros
Investigador principal: Ángel Larrea Arbáizar
43. Método de análisis de tipo magnético para la determinación de formas
submicrométricas de presencia de hierro en régimen diluido y su aplicación a la
caracterización de tamices moleculares, fármacos y sistemas biológicos
Código: PB98-1606
Fuente de financiación: MCyT
Importe total: 49.884 euros
Investigador principal: Francisco José Lázaro Osoro
44. Mejora del polietileno de interposición en prótesis totales articulares y evaluación de
mecanismos de fallos
Código: MAT2000-1278
Fuente de financiación: MCyT
Importe total: 104.336 euros
Investigador principal: José Antonio Puértolas Ráfales
45. Mejoras en las propiedades superconductoras de barras texturadas por fusión zonal
láser debido a la presencia de la fase Bi-2223
Código: HP2001-0008
Fuente de financiación: MCyT
Importe total: 2.644 euros
Investigador principal: Luis Alberto Angurel Lambán
46. Monocristales de manganitas laminares: Crecimiento y estudio de sus propiedades
magnéticas, magnetotransporte y efectos de magnetovolumen
Código: HB1999-0056
Fuente de financiación: MCyT
Importe total: 7.753 euros
Investigador principal: Clara I. Marquina García
47. Motores con imanes permanentes: Optimización dinámica, evaluación de la corrosión
de los imanes y nuevos procesos de preparación de materiales para imanes
permanentes
151
Código: MAT2000-0107-P4-02
Fuente de financiación: MCyT
Importe total: 114.914 euros
Investigador principal: Javier Rubín Llera
48. Nanoestructuras con propiedades magnéticas controladas por efectos de interfac y
de deformación interna
Código:
Fuente de financiación: MCyT
Importe total:
Investigador principal: Miguel Ciria Remacha
49. Nanoimanes moleculares
Código: MAT2002-00433
Fuente de financiación: MCyT
Importe total: 80.648 euros
Investigador principal: Javier Campo Ruíz
50. Nuevos aminoácidos en forma enantioméricamente pura. Diseño, síntesis e
incorporación en péptidos con interés estructural, industrial y/o biológico
Código: PPQ2001-1834
Fuente de financiación: MCyT
Importe total: 156.300 euros
Investigador principal: Carlos Cativiela Marín
51. Nuevos materiales cristal líquidos para
optoelectrónicas
Código: MAT2000-1293-C02-01
Fuente de financiación: MCyT
Importe total: 132.223 euros
Investigador principal: José Luis Serrano Ostáriz
aplicaciones
electroópticas
y
52. Ondas electromagnéticas en medios periódicos
Código:
Fuente de financiación: MCyT
Importe total: 10.602 euros
Investigador principal: Luis Martín Moreno
53. Organoderivados de diversos metales de transición: síntesis, caracterización,
estudio de sus propiedades y sus posibles aplicaciones
Código: PB98-1595-C02-01
Fuente de financiación: MCyT
Importe total: 150.253 euros
Investigador principal: Juan Forniés Gracia
54. Polímeros funcionales para aplicaciones en óptica lineal y no lineal
Código: MAT2002-04118-C02-01
Fuente de financiación: MCyT
Importe total: 201.620 euros
Investigador principal: Joaquín Barberá Gracia
55. Polímeros funcionales para aplicaciones en óptica lineal y óptica no lineal
Código: MAT2002-04118-C02-02
Fuente de financiación: MCyT
Importe total: 125.500 euros
Investigador principal: Rafael Alcalá Aranda
56. Preparación de catalizadores heterogéneos enantioselectivos basados en arcillas
pilareadas
Código:
152
Fuente de financiación: MAE
Importe total: 21.000 euros
Investigador principal: José Antonio Mayoral Murillo
57. Preparación y estudio teórico de complejos heteropolinucleares de oro y talio
Código: 2003CL0017
Fuente de financiación: MCyT
Importe total:
Investigador principal: Antonio Laguna Castrillo
58. Procesado por láser de cerámicos estructurales avanzados
Código: MAT2000-1533-C03-02
Fuente de financiación: MCyT
Importe total: 92.892 euros
Investigador principal: José Ignacio Peña Torre
59. Procesamiento por láser de compuestos laminados para aplicaciones estructurales
Código: MAT2003-06085-C03-01
Fuente de financiación: MCyT
Importe total: 120.500 euros
Investigador principal: José Ignacio Peña Torre
60. Propiedades ópticas lineales y no lineales de materiales polímeros con estructura
cristal líquido
Código: MAT1999-1009-C02-01
Fuente de financiación: MCyT
Importe total: 112.389 euros
Investigador principal: Rafael Alcalá Aranda; Luis T. Oriol Langa
61. Reacciones estequiométricas y catalíticas de acoplamiento carbono-carbono y
carbono-heteroátomo promovidas por complejos de metales de transición
Código: BQU2002-00606
Fuente de financiación: MCyT
Importe total: 327.400 euros
Investigador principal: Miguel Ángel Esteruelas Rodrigo
62. Relación estructura/reactividad en complejos polinucleares de rodio e iridio
Código: BQU2002-01729
Fuente de financiación: MCyT
Importe total: 82.538 euros
Investigador principal: Fernando José Lahoz Díaz
63. Relajación magnética cuántica y diagrama de fases de sistemas de moléculas imán
Código: BFM2003-03919-C02-01
Fuente de financiación: MCyT
Importe total: 21.825 euros
Investigador principal: Julio Fernando Fernández Novoa
64. Síntesis asimétrica de análogos de nucleósidos
Código: BQU2001-2428
Fuente de financiación: MCyT
Importe total: 158.968 euros
Investigador principal: Pedro Merino Filella
65. Síntesis, caracterización y reactividad de complejos de paladio y platino con
fosfoiluros y ligandos relacionados. Procesos de activación C-H, C-P y C-C
Código: BQU2002-00510
Fuente de financiación: MCyT
Importe total: 32.000 euros
Investigador principal: Rafael Navarro Martín
153
66. Síntesis de hidantoínas racémicas 5-sustituidas precursoras de aminoácidos
ópticamente puros por vía enzimática
Código: PPQ2000-0322-P4-02
Fuente de financiación: MCyT
Importe total: 108.182 euros
Investigador principal: José Antonio Mayoral Murillo
67. Síntesis y caracterización de organocomplejos quirales en el metal: Aplicaciones en
catálisis enantioselectiva
Código: BQU200-0907
Fuente de financiación: MCyT
Importe total: 148.953 euros
Investigador principal: José Daniel Carmona Gascón
68. Síntesis y estudio estructural de péptidos modelo que incorporan análogos
restringidos de finilalanina
Código: PPQ2002-00819
Fuente de financiación: MCyT
Importe total: 6.000 euros
Investigador principal: Ana Isabel Jiménez Sanz
69. Síntesis, estructura y reactividad de complejos como y polimetálicos con posibles
propiedades catalíticas o conductoras
Código: BQU2002-00074
Fuente de financiación: MCyT
Importe total: 95.400 euros
Investigador principal: Miguel Ángel Ciriano López
70. Teoría y simulación de sistemas complejos
Código: BFM2002-00113
Fuente de financiación: MCyT
Importe total: 65.000 euros
Investigador principal: Fernando Falo Forniés
2.2.3.- Financiación de las Comunidades Autónomas
Regional Funding
1. Aminoácidos y péptidos
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 19.546 euros
Investigador principal: Carlos Cativiela Marín
2. Actividad catalítica de compuestos heterometálicos early-late en reacciones de
hidroformilación de alquenos
Código: P051/2000
Fuente de financiación: DGA
Importe total: 44.467 euros
Investigador principal: Jesús Julián Pérez Torrente
3. Análogos de nucleósidos. Síntesis de compuestos de alto interés biológico por
métodos selectivos.
Código: P116/2001
Fuente de financiación: DGA
Importe total: 18.030 euros
Investigador principal: Tomás Tejero López
154
4. Aplicación de la tecnología láser para la mejora del valor añadido de productos
basados en yeso y escayola
Código: 02/COOPERA/PR1560
Fuente de financiación: DGA
Importe total: 30.000 euros
Investigador principal: Luis Alberto Angurel Lambán
5. Biomateriales
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 17.628 euros
Investigador principal: José Antonio Puértolas Ráfales
6. Caracterización de materiales mediante técnicas de radiación de sincrotrón
(CAMRADS)
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 18.179 euros
Investigador principal: Joaquín García Ruíz
7. Catálisis heterogéneas en síntesis orgánicas selectivas
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 12.528 euros
Investigador principal: José Antonio Mayoral Murillo
8. Compuestos complejos de paladio: Su utilización como catalizadores homogéneos en
síntesis orgánica y estudio de su retención en membranas de zeolitas
Código: P061/2001
Fuente de financiación: DGA
Importe total: 21.035 euros
Investigador principal: Rafael Navarro Martín
9. Cristales líquidos y polímeros
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 45.703 euros
Investigador principal: José Luis Serrano Ostáriz
10. Desarrollo de nuevos materiales magnéticos de alto interés tecnológico: Nuevas
rutas de síntesis y de caracterización microscópica
Código: P004/2001
Fuente de financiación: DGA
Importe total: 13.523 euros
Investigador principal: Jesús Chaboy Nalda
11. Especiación del hierro biológico
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 5.842 euros
Investigador principal: Francisco José Lázaro Osoro
12. Estructura y función de proteínas y genes de plantas
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 17.955 euros
Investigador principal: Rafael Picorel Castaño
155
13. Estudio de compuestos magnéticos con propiedades tecnológicas utilizando altos
campos magnéticos pulsados
Código: MP09/2003
Fuente de financiación: DGA
Importe total: 2.000 euros
Investigador principal: Pedro Algarabel Lafuente
14. Estudio de los efectos de la corrosión de imanes permanentes y de las pérdidas ac
en cintas e hilos superconductores mediante la aplicación de campos magnéticos
alternos de intensidad media (0.1 T)
Código: P018/2001
Fuente de financiación: DGA
Importe total: 34.589 euros
Investigador principal: Agustín Camón Lasheras
15. Estudio de las propiedades antitumorales de complejos de oro
Código: P076/2000
Fuente de financiación: DGA
Importe total: 24.040 euros
Investigador principal: María Concepción Gimeno Floría
16. Estudio, mediante técnicas de resonancia paramagnética electrónica en onda
continua y en el dominio temporal, de citocromos de la cadena de transporte electrónico
fotosintético
Código: P111/2001
Fuente de financiación: DGA
Importe total: 24.000 euros
Investigador principal: Jesús Ignacio Martínez Martínez
17. Física estadística y no lineal
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 10.855 euros
Investigador principal: Luis Mario Floría Peralta
18. IMANA
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 24.000 euros
Investigador principal: Juan Bartolomé Sanjoaquín
19. Magnetismo de sólidos
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 22.382 euros
Investigador principal: Agustín del Moral Gámiz
20. Materiales moleculares electro fotoactivos
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 5.494 euros
Investigador principal: Vicente Javier Garín Tercero
21. Materiales procesados por láser: Preparación y caracterización
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 15.751 euros
Investigador principal: Víctor Orera Clemente
22. Memorias magnéticas basadas en el efecto túnel polarizado en espín
156
Código: CTPR03/2002
Fuente de financiación: DGA
Importe total: 12.000 euros
Investigador principal: José María de Teresa Nogueras
23. Nanocomposites magnéticos de matríz polimérica: Preparación, caracterización
microscópica, propiedades magnéticas y estudio de aplicaciones
Código: CTP2001-I+D
Fuente de financiación: DGA
Importe total: 12.422 euros
Investigador principal: Fernando Palacio Parada
24. Organometálicos y catálisis
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 18.618 euros
Investigador principal: Miguel Ángel Esteruelas Rodrigo
25. Propiedades espectroscópicas de iones Pr3+ en cristales de BaFCI, BaFBr y
mezclados BaFCIxBr1-x.
Código: P069/2000
Fuente de financiación: DGA
Importe total: 15.326 euros
Investigador principal: Rafael Cases Andreu
26. Química bioorgánica
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 19.546 euros
Investigador principal: Pedro Merino Filella
27. Química de la coordinación y catálisis homogéneas
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 55.803 euros
Investigador principal: Luis Oro Giral
28. Renovación y ampliación del servicio de medidas magnéticas
Código:
Fuente de financiación: DGA
Importe total: 580.000 euros
Investigador principal: Conrado Rillo Millán
29. Síntesis asimétrica de aminoácidos no-proteinogénicos y su incorporación en
pequeños péptidos
Código: P22/98
Fuente de financiación: DGA
Importe total: 90.152 euros
Investigador principal: Carlos Cativiela Marín
30. Síntesis, caracterización y propiedades ópticas no lineales de nuevos cromóforos de
tipo merocianina
Código: P009/2001
Fuente de financiación: DGA
Importe total: 18.030 euros
Investigador principal: Vicente Javier Garín Tercero
31. Síntesis y propiedades físicas de nanoimanes moleculares obtenidos por nuevos
métodos de síntesis
Código: CTP2002
157
Fuente de financiación: DGA
Importe total: 6.000 euros
Investigador principal: Javier Campo Ruíz
32. Sistemas de microanálisis por rayos X para los microscopios de barrido y
transmisión de SAI
Código:
Fuente de financiación: DGA
Importe total: 165.019 euros
Investigador principal: Ángel Larrea Arbáizar
33. Sistemas de suspensión activo para uso en asientos de vehículos y maquinaria
Código: P085/2001
Fuente de financiación: DGA
Importe total: 18.000 euros
Investigador principal: Mario Vicente Maza Frechín
34. Superconductividad aplicada
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 28.294 euros
Investigador principal: Rafael Navarro Linares
35. Técnicas de prototipado virtual basadas en voxeles. Técnicas de prototipado rápido
basadas en láser. Proyecto PV-VOXEL-PPR LASER
Código: P055/2000
Fuente de financiación: DGA
Importe total: 36.000 euros
Investigador principal: Francisco Serón Arbeola
36. TERMOMAG
Código: Grupo de Investigación reconocido por la DGA
Fuente de financiación: DGA
Importe total: 19.342 euros
Investigador principal: Fernando Palacio Parada
37. Vanguardia, tradición y desarrollos tecnológicos en la cerámica tradicional
aragonesa
Código: 02/COOPERA/ES1368
Fuente de financiación: DGA
Importe total: 81.250 euros
Investigador principal: Germán de la Fuente Leis
38. Versatilidad del anillo de isoaloxazina como Centro Redox. Implicaciones en
procesos de transferencia electrones entre proteínas
Código: BQU2001/2520
Fuente de financiación: DGA
Importe total: 30.000 euros
Investigador principal: Milagros Medina Trullenque
2.2.4.- Financiación de la Industria
Industrial Funding
1. Análisis y caracterización estructural de compuestos y materiales químicos (Apoyo
tecnológico)
Código:
Fuente de financiación: DGA
Importe total: 60.101 euros
158
Investigador principal: Fernando José Lahoz Díaz
2. Análisis y optimización de caja de coche de metro en materiales avanzados
Código:
Fuente de financiación: Metro Madrid, S.A.
Importe total: 191.978 euros
Investigador principal: Antonio Miravete de Marco
3. Caracterización de materiales poliméricos
Código:
Fuente de financiación: Cogullada Castellón, S.L.
Importe total: 11.500 euros
Investigador principal: José Antonio Mayoral Murillo
4. Caracterización del proceso de polimerización de pastas resistivas mediante
calorimetría diferencial de barrido y correlación con medidas eléctricas
Código: OTRI 2002/0297
Fuente de financiación: Aragonesa de Componentes Pasivos
Importe total: 3.866 euros
Investigador principal: Miguel Castro Corella
5. Contrato de colaboración entre el CSIC y la empresa Bruker Española, S.A. para la
creación del “Centro de Excelencia ICMA-Bruker” en difracción de rayos X en el ICMA
Código:
Fuente de financiación: Bruker Española, S.A.
Importe total: 180.303 euros
Investigador principal: Fernando José Lahoz Díaz
6. Desarrollo de estructuras cristalinas mediante procesado láser
Código:
Fuente de financiación: Colorobbia España, S.A.
Importe total: 63.000 euros
Investigador principal: Germán de la Fuente Leis
7. Estudio de reducción de peso en coche de alta velocidad mediante el uso de la
tecnología
Código:
Fuente de financiación: Patentes Talgo, S.A.
Importe total: 12.000 euros
Investigador principal: Antonio Miravete de Marco
8. Mecanizado láser de fibra de carbono para industria aeronáutica. Estudio del
procesado por láser y metodología de corte. Implantación del sistema en planta
Código: PROFIT-100100-2003-1
Fuente de financiación: Empresa Airbus
Importe total: 45.000 euros
Investigador principal: José Ignacio Peña Torre
9. Modificación de superficies de baldosas cerámicas por láser
Código:
Fuente de financiación: Gres de Nules, S.A.
Importe total: 66.110 euros
Investigador principal: Germán de la Fuente Leis
10. Optimización y automatización de dos comparadores criogénicos de corriente
Código: OTRI 2003/366
Fuente de financiación: TPYCEA
Importe total: 180.000 euros
Investigador principal: Conrado Rillo Millán
159
11. Recubrimientos DLC mediante PECVD para la mejora de las propiedades barrera de
botellas de plástico a gases y disolventes
Código: OTRI 2002/0094
Fuente de financiación: EDP, S.A.
Importe total: 46.309 euros
Investigador principal: Miguel Castro Corella
12. Recubrimientos DLC mediante PECVD para la mejora de las propiedades barrera de
botellas de plástico a gases y disolventes
Código: OTRI 2003/0094
Fuente de financiación: EDP, S.A.
Importe total: 67.566 euros
Investigador principal: Miguel Castro Corella
13. Síntesis de dihidrofenilglicina
Código: OTRI 2002/0356
Fuente de financiación: DSM Deretil
Importe total: 12.000 euros
Investigador principal: Carlos Cativiela Marín
14. Magnetic permeability measurements on stainless steel simples for LHC
Código:
Fuente de financiación: DMV Stainless Italia, Bohler
Importe total: 150.602,40 euros
Investigador principal: Conrado Rillo Millán
15. Propiedades magnéticas de aleaciones intersticiales por reacción gas-sólido
Código:
Fuente de financiación: Fundación Domingo Martínez
Importe total: 6.000 euros
Investigador principal: Juan Bartolomé Sanjoaquín
160
2.3.- Divulgación Científica
Scientific Dissemination
161
2.3.1.- Actividades
Activities
El ICMA ha participado activamente en
diferentes actos de divulgación científica
organizados tanto por la Universidad de
Zaragoza como por el Consejo Superior de
Investigaciones Científicas.
Entre ellas,
podemos destacar:
APERTA: LA UNIVERSIDAD EN LA CALLE
Zaragoza, 25 a 28 de septiembre de 2003.
El Rectorado y el Consejo Social de la
Universidad de Zaragoza - en colaboración con
el Gobierno de Aragón, el Ayuntamiento de
Zaragoza, Ibercaja y Caja Inmaculada organizaron unas jornadas de puertas abiertas.
Se trataba de una iniciativa con la que la
Universidad de Zaragoza quería abrirse y
acercarse más a la sociedad, tanto a los
colectivos educativos como a las empresas de
su entorno y al público en general. Uno de sus
objetivos consistía en informar sobre las
titulaciones de todos sus centros y títulos
propios, así como de todas las actividades, tanto
formativas como investigadoras y de servicio a
la sociedad en su conjunto.
El ICMA participó en estas jornadas
confeccionando tanto dípticos como pósters,
que se presentaron en la carpa del Instituto
junto con materiales producidos en sus trabajos.
Diversos miembros del ICMA impartieron
conferencias a lo largo de los cuatro días:
- “La tecnología láser en la restauración del
patrimonio artístico y cultural”, por R. Lahoz.
- “Pilas de combustible: una posible energía
para el futuro”, por M.A. Laguna.
- “El estado del cristal líquido: su belleza y sus
aplicaciones”, por L. Oriol y T. Sierra.
The ICMA participated in various scientific
dissemination activities organized by the
University of Zaragoza and the Spanish Council
for Scientific Research. Among the highlighs are
the following:
APERTA: THE UNIVERSITY IN THE STREET
Zaragoza, 25th to 28th September, 2003.
The Rectorate and the Social Council of the
University of Zaragoza, in collaboration with the
Government of Aragón, the City Council of
Zaragoza, the savings institutions Ibercaja and
Caja Inmaculada, organized this event as as
series of open-door activities. The University
participated with outreach activities directed at
local schools, businesses and the general
public. One of the main aims of this participation
was to further public awareness of the major
study programs available at the university as
well as of its varied training, research and
community service programs.
The ICMA participated in these activities
with its own stand, brochures and posters,
together with sample materials from our own
laboratories and eye-catching demonstrations.
Members of ICMA presented lectures as
part of the four-day program:
- “Laser technology in the restoration of cultural
heritage”, R. Lahoz.
- “Fuel-Cells: a possible energy for the future”,
M. A. Laguna
- “The liquid crystal state: its beauty and its
applications”, L. Oriol and T. Sierra.
163
SEMANA DE LA CIENCIA: DESCUBRE EL
CSIC EN ARAGÓN
Zaragoza, 10 al 14 de noviembre de 2003
SCIENCE WEEK: DISCOVER THE CSIC IN
ARAGÓN
Zaragoza, 10th to 14th November, 2003
Dentro de las actividades de la “Semana de la
Ciencia y la Tecnología”, la delegación del CSIC
en Aragón organizó una exposición en la que se
presentaban los diferentes Centros del CSIC en
Aragón. La delegacion, con esta exposición,
intentaba acercar a los estudiantes de nuestra
comunidad la labor desarrollada en los Institutos
de Investigación que el CSIC tiene en Aragón.
La exposición incluía: posters, videos de
divulgación científico-técnica, demostraciones,
conferencias, etc.
También se organizaron unas Jornadas de
Puertas Abiertas dentro de los Institutos.
Una de las actividades programadas consistió
en la conferencia impartida por J. L. Serrano y
titulada “Cristales líquidos: Organizaciones
supramoleculares en nuestras vidas”.
As part of “Science and Technology Week”, the
delegation of the CSIC in Aragón organized an
exposition in which the activities of the CSIC
centers in our region were presented. The aim
of this activity was to introduce students from all
over Aragón to the scientific work being carried
out by the CSIC Institutes in this region.
Posters, demonstrations, lectures, and a
popular-science video were all included in the
program.
In addition, open-door visits to the different
Institutes were organized during the course of
the week.
One of the activities was a lecture given by J. L.
Serrano:
“Liquid Crystals: Supramolecular
organizations in our lives”.
164
2.3.2.- Proyectos
Grants
1. Acciones de difusión y divulgación de
la ciencia y la tecnología.
Código: DIF2003-10374-E
Fuente de financiación: MCyT
Importe total: 7.725 euros
Investigador principal: Ramón Burriel
Lahoz
2. Celebración de la Semana de la
Ciencia.
Código: DIF2003-10066-E
Fuente de financiación: MCyT
Importe total: 36.900 euros
Investigador principal: Juan Bartolomé
Sanjoaquín
3. “El circo de la ciencia”.
Código: DIF2003-10375
Fuente de financiación: MCyT
Importe total: 16.000 euros
Investigador principal: Jesús
Martínez Martínez
Ignacio
4. Exposición itinerante “Descubre el
CSIC en Aragón”.
Código: DIF2003-10345-E
Fuente de financiación: MCyT
Importe total: 47.000 euros
Investigador principal: Juan Bartolomé
Sanjoaquín
165
3.- Producción Científica
Scientific Productivity
167
3.1.- Artículos en Revistas Periódicas
Journal Articles
2002
Diseño de tres tipologías de automóviles en
diferentes sistemas de material.
J. Abad, L. Castejón, V. Berrueco, E. Larrodé,
A. Miravete.
CIT 2002, 2233-2241.
The Jahn-Teller vibronic reduction factors in
icosahedral GXG systems.
M. Aboughantous, P. B. Oliete, C. A. Bates, J.
L. Dunn, V. Z. Polinger, R. Huang, S. P. Rough.
J. Phys. Condens. Mat. 2002, 14, 4679-4697.
Composition and temperature dependence of
the magnetocrystalline anisotropy in
Ni2+xMn1+yGa1+z (x+y+z=0) Heusler alloys.
F. Albertini, L. Pareti, A. Pauluzi, L. Morellón, P.
A. Algarabel, M. R. Ibarra, L. Righi.
Appl. Phys. Lett. 2002, 81, 4032-4034.
Effect of impurities on the successive phase
transitions in (Cs1-xRbx)2ZnI4 compounds.
I. P. Aleksandrova, J. Bartolomé, L. R. Falvello,
J. M. Torres, A. A. Sukhovskii.
J. Phys. Condens. Mat. 2002, 14, 13623-13634.
Low-Temperature phase transitions in the
trigonal modification of Cs3Bi2Br9 and
Cs3Sb2I9.
I. P. Aleksandrova, R. Burriel, J. Bartolomé, B.
Sh. Bagautdinov, J. Blasco, A. A. Sukhovsky, J.
M. Torres, A. D. Vasiljev, L. A. Solovjev.
Phase Transit. 2002, 75, 607-620.
Influence of phenyl side chain on the
conformation of cyclopropane analogues of
phenylalanine.
C. Alemán, A. I. Jiménez, C. Cativiela, J. J.
Pérez, J. Casanovas.
J. Phys. Chem. B 2002, 106, 11849-11858.
Field effect on phase segregation in the
electron-doped mixed valence manganites
near a structural instability.
P. A. Algarabel, J. M. de Teresa, B. García
Landa, L. Morellón, M. R. Ibarra, C. Ritter, R.
Mahendiran, A. Maignan, M. Hervieu, C. Martín,
B. Raveau, A. Kurbakov, V. Trounov.
Phys. Rev. B 2002, 65, Art. Nº 104437.
Photoinduced electron-transfer processes in
C60-tetrathiafulvalene dyads containing a
short or long flexible spacer.
E. Allard, J. Cousseau, J. Orduna, J. Garín, H.
Luo, Y. Araki, O. Ito.
Phys. Chem. Chem. Phys. 2002, 4, 5944-5951.
A new family of sulfur-rich ligands based on
the DMIT system: Synthesis and metal
complexation of 4-4'-covalently bridged
bis(2-thioxo-1,3-dithiol-5-thiolato) units.
D. W. Allen, R. Berridge, N. Bricklebank, E.
Cerrada, M. E. Light, M. B. Hursthouse, M.
Laguna, A. Moreno, P. J. Skabara.
J. Chem. Soc. Dalton 2002, 2654-2659.
A new series of homoleptic, high-spin
organochromium derivatives: Synthesis,
characterization and study of their magnetic
properties.
P. J. Alonso, J. Forniés, M. A. García-Monforte,
A. Martín, B. Menjón, C. Rillo
Chem. Eur. J. 2002, 8, 4056-4065.
The
first
structurally
characterised
homoleptic σ-organotitanium (III) compound.
P. J. Alonso, J. Forniés, M. A. García-Monforte,
A. Martín, B. Menjón.
Chem. Commun. 2002, 728-729.
(E)-4-(2-(bis(octadecylsulfanyl)tetrathiafulvalenyl)thenyl)-1-methylpyridinium iodide.
R. Andreu, J. Garín, J. Orduna, G. J. Ashwell, M.
A. Amiri, R. Hamilton.
Thin Solid Films 2002, 408, 236-239.
The
neutral
diradical
5,5'-bis(1,3,2,4dithiadiazolyl) [SNSNC-CNSNS], the first
main group radical to exhibit a dramatic
increase in paramagnetism on mechanical
grinding.
G. Antorrena, S. Brownridge, T. S. Cameron, F.
Palacio, S. Parsons, J. Passmore, L. K.
Thompson, F. Zarlaida.
Can. J. Chem. 2002, 80, 1568-1583.
A luminescent Pt3Pb cluster with three Pt (II)Pb(II) bonds.
I. Ara, L. R. Falvello, J. Forniés, J. Gómez
Cordón, E. Lalinde, R. I. Merino, I. Usón.
J. Organomet. Chem. 2002, 663, 284-288.
Formation of diphenylphosphanylbutadienyl
complexes by insertion of two P-coordinated
alkynyllphosphanes into a Pt-C6F5 bond.
Detection of intermediate and reactionproducts.
I. Ara, J. Forniés, A. García, J. Gómez, E.
Lalinde, M. T. Moreno.
Chem. Eur. J. 2002, 8, 3698-3716.
169
Magnetoelastic stresses in epitaxial (110)
terfenol-d thin-films.
J. I. Arnaudas, C. de la Fuente, M. Ciria, L.
Benito, C. Dufour, K. Dumesnil, A. del Moral.
J. Magn. Magn. Mater. 2002, 240, 389-391.
Synthesis
of
7-azabicyclo[2.2.1]heptane
derivatives via bridgehead radicals.
A. Avenoza, J. H. Busto, C. Cativiela, J. M.
Peregrina.
Tetrahedron 2002, 58, 1193-1197.
Metastable phases in the Ti-V system. I:
Neutron diffraction study of an assessment
of structural properties.
G. Aurelio, A. Fernández Guillermet, G. Cuello,
J. Campo.
Metall. Mater. Trans. A 2002, 33, 1307-1317.
Tandem Diels-Alder cycloaddition/rearrangement: A method for the synthesis of a 2,5,6trisubstituted biphenyl.
A. Avenoza, J. H. Busto, C. Cativiela, J. M.
Peregrina.
Afinidad 2002, 59, 431-434.
Structural properties of metastable phases in
Zr-Nb alloys III. The athermal Omega phase.
G. Aurelio, A. Fernández Guillermet, G. Cuello,
J. Campo.
J. Alloy Comp. 2002, 335, 132-138.
Magnetic flux bifurcation and frequency
doubling in rotated superconductors.
A. Badía, C. López.
J. Appl. Phys. 2002, 92, 6110.
Aspartame analogues containing 1-amino-2phenylcyclohexanecarboxylic acids (c6Phe).
A. Avenoza, M. París, J. M. Peregrina, M. Alías,
M. P. López, J. I. García, C. Cativiela.
Tetrahedron 2002, 58, 4899-4905.
Asymmetric hetero Diels-Alder as an access
to carbacephams.
A. Avenoza, J. H. Busto, C. Cativiela, F.
Corzana, J. M. Peregrina, M. M. Zurbano.
J. Org. Chem. 2002, 67, 598-601.
β-Turn modulation by incorporation of c6Ser
into Xaa-Pro dipeptide.
A. Avenoza, J. H. Busto, C. Cativiela, J. M.
Peregrina, F. Rodríguez.
Tetrahedron Lett. 2002, 43, 1429-1432.
Reactivity
of
(Z)-4-arylidene-5(4H)Oxazolones.
(4+2)-cycloaddition
versus
(4+3)-cycloaddition/nucleophilic trapping.
A. Avenoza, J. H. Busto, C. Cativiela, J. M.
Peregrina.
Tetrahedron Lett. 2002, 43, 4167-4170.
(S)- and (R)-N-Boc-N,O-isopropylidene-αmethylserinals. Preparation, synthesis and
applications.
A. Avenoza, C. Cativiela, F. Corazana, J. M.
Peregrina, D. Sucunza, M. M. Zurbano.
Acros Org. Act. 2002, 9, 9-12.
Synthesis, activity and theoretical study of
ABT-418 analogs.
A. Avenoza, J. H. Busto, C. Cativiela, A. Dordal,
J. Frigola, J. M. Peregrina.
Tetrahedron 2002, 58, 4505-4511.
Synthesis of enantiopure analogs of 3hydroxyproline and derivatives.
A. Avenoza, J. I. Barriobero, J. H. Busto, C.
Cativiela, J. M. Peregrina.
Tetrahedron: Asymmetry 2002, 13, 625-632.
Vector
magnetic
hysteresis
of
superconductors.
A. Badía, C. López.
Phys. Rev. B 2002, 65, Art. Nº 104514.
hard
Highly convergent steroselective synthesis
of chiral key intermediates in the synthesis
of Palinavir from imines derived from Lglyceraldehyde.
R. Badorrey, C. Cativiela, M. D. Díaz de
Villegas, J. A. Gálvez.
Tetrahedron 2002, 58, 341-354.
Stereodivergent
addition
of
allylmetal
reagents to imines derived from (R)-2,3-di-0benzylglyceraldehyde
by
appropriate
selection
of
metal
and
double
stereodifferentiation.
R. Badorrey, C. Cativiela, M. D. Díaz de
Villegas, J. A. Gálvez.
Eur. J. Org. Chem. 2002, 3763-3767.
Tert-Butyl(7R)-7[(4S)-2,2-dimethyl-[1,3]dioxolan-4-yl]-1,4-diona-8-azaspirol[4.5]decane-8carboxylate.
R. Badorrey, C. Cativiela, M. D. Díaz de
Villegas, J. A. Gálvez.
Acta Crystallogr. E 2002, 58, 750-752.
Dendrimers with laterally grafted mesogens.
J. Barberá, R. Giménez, M. Marcos, J. L.
Serrano.
Liq. Cryst. 2002, 29, 309-314.
Chiral
hexacatenar
metallomesogens:
Supramolecular organization versus steric
demand of chiral cores.
J. Barberá, M. Lehmann, J. L. Serrano, T.
Sierra.
J. Mater. Chem. 2002, 12, 1342-1350.
Unexpected ring-opening reaction to a new
cyanamide-thiolate ligand stabilized as a
dinuclear gold complex.
M. Bardají, A. Laguna, M. R. Pérez, P. G. Jones.
Organometallics 2002, 21, 1877-1881.
170
Aurophilic complexes as gold atom sources
in organic media.
M. Bardají, P. Uznanski, C. Amiens, B.
Chaudret, A. Laguna.
Chem. Commun. 2002, 598-599.
Acetylenephosphino
gold(I)
derivatives:
Structure, reactivity and luminescence
properties.
M. Bardají, P. G. Jones, A. Laguna.
J. Chem. Soc. Dalton 2002, 3624-3629.
Synthesis of 2,4,6-tris(trifluoromethyl)phenyl
complexes of gold and thallium.
M. Bardají, P. G. Jones, A. Laguna, A. Moracho,
A. K. Fischer.
J. Organomet. Chem. 2002, 648, 1-7.
Reactions
of
an
osmium-elongated
dihydrogen complex with terminal alkynes.
Formation of novel bifunctional compounds
with amphoteric nature.
P. Barrio, M. A. Esteruelas, E. Oñate.
Organometallics 2002, 21, 2491-2503.
Magnetoresistance and spin electronics.
A. Barthelemy, A. Fert, J. P. Contour, M. Bowen,
V. Cros, J. M. de Teresa, A. Hamzic, G. Faini, J.
M. George, J. Grollier, F. Montaigne, F. Pailloux,
F. Petroff, C. Vouille.
J. Magn. Magn. Mat. 2002, 242, 68-76.
Negative
magnetization
and
segregation in NdMnO3+δ.
F. Bartolomé, J. Bartolomé, J. Campo.
Physica B 2002, 312-313, 769-771.
phase
Manganese(II), Copper(II), Nickel(II) and
Cobalt(II)
hexafluoroacetylacetonate
complexes
with
tetrakis(N-oxyl-2,2,6,6tetramethylpiperidin-4-oxyl)silane.
M. Baskett, P. M. Lahti, F. Palacio.
Abstr. Papers Am. Chem. 2002, 224, 1193.
Hydride-carbyne to carbene trasformation in
a cyclopentadienyl-osmium complex: An
alternative to the single hydride-cα migration.
M. Baya, M. A. Esteruelas.
Organometallics 2002, 21, 2332-2335.
Lewis base-assisted hydride-carbyne to
olefin
transformation
versus
carbene
formation.
M. Baya, M. A. Esteruelas, E. Oñate.
Organometallics 2002, 21, 5681-5684.
Regioselective addition of dienes to the Cβ-Cγ
double-bond of the allenylidene ligand of
[Ru(η5-C5H5)(=C=C=CPh2)(CO)((PiPr3]BF4.
M. Baya, M. L. Buil, M. A. Esteruelas, A. M.
López, E. Oñate, J. R. Rodríguez.
Organometallics 2002, 21, 1841-1848.
Double-channel excitation in the X-ray
3+
absorption spectrum of Fe water solutions.
M. Benfatto, J. A. Solera, J. García, J. Chaboy.
Chem. Phys. 2002, 282, 441-450.
Magnetoelasticity of single crystal SmFe2
(110) thin film.
L. Benito, C. de la Fuente, M. Ciria, J. I.
Arnaudas, A. del Moral, A. Mougin, K. Dumesnil.
J. Magn. Magn. Mat. 2002, 242-245, 14501452.
Binuclear mesogenic copper(I) isocyanide
complexes with an unusual inorganic core
formed by two tetrahedral sharing an edge.
M. Benouazzane, S. Coco, P. Espinet, J. M.
Martín Alvarez, J. Barberá.
Inorg. Chem. 2002, 41, 5754-5759.
Liquid crystalline behaviour in gold(I) and
silver(I) ionic isocyanide complexes: smectic
and columnar mesophases.
M. Benouazzane, S. Coco, P. Espinet, J. M.
Martín Alvarez, J. Barberá.
J. Mater. Chem. 2002, 12, 691-696.
Diphenyl(phenylethynyl)phosphine d6 [Rh(III),
Ir(III), Ru(II)] complexes. Preparation of homo
(µ-Cl)2 and hetero (µ-Cl)(µ-PPh2C≡CPh)
bridged d6-d8 compounds.
J. H. Berenguer, M. Bernechea, J. Forniés, J.
Gómez, E. Lalinde.
Organometallics 2002, 21, 2314-2324.
Facilitated transport of O2- through aluminazeolite composite membranes containing a
solution with a reducible metal-complex.
M. P. Bernal, M. Bardají, J. Coronas, J.
Santamaría.
J. Membrane Sci. 2002, 203, 209-213.
A pentanuclear mixed gold(III)-silver(I)
phosphide with an unusual T-frame µ3-Cl
bridge.
M. C. Blanco, E. J. Fernández, M. E. Olmos, O.
Crespo, A. Laguna, P. G. Jones.
Organometallics 2002, 21, 2426-2429.
Structural, magnetic and transport properties
of Sr2Fe1-xCrxMoO6-y.
J. Blasco, C. Ritter, L. Morellón, P. A. Algarabel,
J. M. de Teresa, D. Serrate, J. García.
Solid State Sci. 2002, 4, 651-660.
Synthesis and structural study of
La(Ni1-xMnx)O3+y perovskites.
J. Blasco, M. C. Sánchez, J. Pérez-Cacho, J.
García, G. Subías, J. Campo.
J. Phys. Chem. Solids 2002, 63, 781-792.
Neutron diffraction study and magnetic
properties of LaMn1-xGaxO3.
J. Blasco, J. García, J. Campo, M. C. Sánchez,
G. Subías.
Phys. Rev. B 2002, 66, Art. Nº 174431.
171
Magnetic properties of La(Ni1-xMnx)O3+y
perovskites.
J. Blasco, J. García, M. C. Sánchez, J. Campo,
G. Subias, J. Pérez-Cacho.
Eur. Phys. J. B 2002, 30, 469-479.
Synthesis, characterization and catalytic
activity
in
Heck-type
reactions
of
orthometallated Pd(II) and Pt(II) complexes
derived
from
(1R,2R)-1,2diaminocyclohexane.
J. Bravo, C. Cativiela, R. Navarro, E.
Urriolabeitia.
J. Organomet. Chem. 2002, 650, 157-172.
Improvement of ligand economy controlled
by polymer morphology: the case of
polymer-supported bis(oxazoline) catalysts.
M. I. Burguete, E. Díez Barra, R. González, J. M.
Fraile, J. I. García, E. García Verdugo, S. V.
Luis, J. A. Mayoral.
Bioorg. Chem. Med. Lett. 2002, 12, 1821-1824.
Electrostatic vs. covalent immobilization of
bis(oxazoline) complexes.
M. I. Burguete, J. M. Fraile, J. I. García, M. J.
Gil, C. Herrerías, S. V. Luis, V. Martínez Merino,
J. A. Mayoral.
Afinidad 2002, 59, 449-453.
Orientational phase transition of (CH3)4NCIO4
in two and three dimensions.
R. Burriel, E. Palacios, J. J. Melero, P. Ferloni.
Ferroelectrics 2002, 270, 393-398.
In search of optically active γ-keto
acetylenes via regioselective coupling of
allenylidene groups and cyclic enolates.
V. Cadierno, S. Conejero, M. P. Gamasa, J.
Gimeno, L. R. Falvello, R. M. Llusar.
Organometallics 2002, 21, 3716-3726.
Neutron diffraction study of the structural
phase transition in the deuterated molecular
ferromagnet Fe(dtc)2Cl.
J. Campo, J. Luzón, F. Palacio, G. DeFotis, J.
Christophel, E. Ressouche.
Appl. Phys. A: Mater. 2002, 74, 8923-8925.
Gold and silver complexes with the ligands
5
Fc(SPh)2 and Fc(SePh)2 (Fc=(η -C5H4)2Fe).
S. Canales, O. Crespo, A. Fortea, M. C.Gimeno,
P. G. Jones, A. Laguna.
J. Chem. Soc. Dalton, 2002, 2250-2255.
Two- and four-electron-alkyne ligands in
osmium-cyclopentadienyl
chemistry:
Consequences of the pi-M interaction.
J. J. Carbó, P. Crochet, M. A. Esteruelas, Y.
Jean, A. Lledós, A. M. López, E. Oñate.
Organometallics 2002, 21, 305-314.
Half-sandwich complexes with chiral ligands
and their use as enantioselective catalysts
(microreview).
D. Carmona, M. P. Lamata, L. A. Oro.
Eur. J. Inorg. Chem. 2002, 2239-2251.
Synthesis, characterization, properties, and
asymmetric catalytic Diels-Alder of chiral-atmetal phosphinooxazoline-Rhodium(III) andIridium(III) complexes.
D. Carmona, F. J. Lahoz, S. Elipe, L. A. Oro, M.
P. Lamata, F. Viguri, F. Sánchez, S. Martínez,
C. Cativiela, M. P. López Ram-de-Víu.
Organometallics 2002, 21, 5100-5114.
Preparation and properties of Rh(I) and Ir(I)
ethylene complexes containing the chiral
P,N-chelate
ligand
(4S)-2-(2(diphenylphosphanyl)phenyl)-4-isopropyl-13-oxazoline.
D. Carmona, J. Ferrer, E. Lalaguna, M. Lorenzo,
F. J. Lahoz, S. Elipe, L. A. Oro.
Eur. J. Inorg. Chem. 2002, 259-263.
Diastereoselective formation of chiral Iridium
hydrides containing the chiral P,N-chelate
ligand (4S)-2-(2-(diphenylphosphino)phenyl)4-isopropyl-1,3-oxazoline.
D. Carmona, J. Ferrer, M. Lorenzo, M.
Santander, S. Ponz, F. J. Lahoz, J. A. López, L.
A. Oro .
Chem. Commun. 2002, 870-871.
On the sense of the enantioselection in
hydrogen-transfer reactions from 2-propanol
to ketones.
D. Carmona, M. P. Lamata, F. Viguri, I.
Dobrinovich, F. J. Lahoz, L. A. Oro
Adv. Synth. Catal. 2002, 344, 499-502.
Synthesis
and
molecular-structure
of
[{(HBpz3)Rh(PPh3)(µ-CI)2}2Ag]BF4 (Hpz=Pyrazole), a heterotrinuclear Rh2Ag compound
with square-planar silver(I).
D. Carmona, F. Viguri, F. J. Lahoz, L. A. Oro.
Inorg. Chem. 2002, 41, 2385-2388.
Mono(p-tolyl)platinum(II)
and
bis(ptolyl)platinum(II) complexes of diethylsulfide
as reagents for organoplatinum synthesis.
Structures of [Pt(p-Tol)2(µ-SEt2)]2 and [PtCl(pTol)2(bpy)] (bpy = 2,2´-bipyridine).
M. A. Casado, A. J. Canty, M. Lutz, J. Patel, A.
Spek , H. Sun, H. G. van Koten.
Inorg. Chim. Acta 2002, 327, 15-19 .
Synthesis of a dinuclear platinum-silver
complex containing a reactive acetone imine
prepared in situ from acetone and ammonia
and stabilized by metal complexations.
J. M. Casas, J. Forniés, A. Martín, A. J. Rueda.
Organometallics 2002, 21, 4560-4563.
Ensayo de vuelco de autobuses con
carrocerías de materiales poliméricos.
L. Castejón, J. Cuartero, N. Tolosana, A.
Miravete.
CIT 2002, 2251-2262.
172
In situ hydration of Portland cement
monitored by neutron diffraction.
M. Castellote, C. Alonso, C. Andrade, J. Campo,
X. Turrillas.
Appl. Phys. A: Mater. 2002, 74, S1224-S1226.
Application of the synchrotron radiation to
the study of the microstructure changes in
cement paste due to accelerated leaching by
application of electrical fields.
M. Castellote, X. Turrillas, C. Andrade, C.
Alonso, A. Kvick, A. Terry, G. Vaughan, J.
Campo.
J. Am. Ceram. Soc. 2002, 85, 3, 631-635.
The use of solid acids to promote the onepot
synthesis
of
d,l-5-(4hydroxyphenyl)hydantoin.
C. Cativiela, J. M. Fraile, J. I. García, B. Lázaro,
J. A. Mayoral, A. Pallarés.
Appl. Catal. A: Gen. 2002, 224, 153–159.
Ortho-metalated benzenethiolate bridging
dinuclear Palladium(II) complexes. X-ray
t
structures of [Sn2(µ-C6H4S)2( Bu)4] and [Pd2(µ
-C6H4S)( µ -dppm)2Cl2].
M. Cera, E. Cerrada, M. Laguna, J. A. Mata, H.
Teruel.
Organometallics 2002, 21, 121-126.
Tetrathiafulvalene-functionalized
phospine
as a coordinating ligand. X-ray structures of
(PPh2)4 TTF and (AuCl)4(PPh2)4TTF).
E. Cerrada, C. Díaz, M. C. Díaz, M. B.
Hursthouse, M. Laguna, M. E. Light.
J. Chem. Soc. Dalton 2002, 1104-1109.
PPh(2-C6H4S)2 as a pincer ligand in Nickel(II)
and Palladium(II) complexes - X-ray structure
of
[Ni{PPh(C6H4S)2}(PPh2Me)],
[Pd2(µdppe){PPh(C6H4S)2}2] and [Ni(PPh(C6H4S)2)]2.
E. Cerrada, L. R. Falvello, M. B. Hursthouse, M.
Laguna, A. Luquín, C. Pozo-Gonzalo.
Eur. J. Inorg. Chem. 2002, 826-833.
Magnetoelastic
coupling
in
epitaxial
Cu/Ni90Fe10/Cu/Si(001) films.
M. Ciria, K. Ha, D. Bono, R. C. O´Handley.
J. Appl. Phys. 2002, 91, 8150-8152.
Surface and strain induced anisotropy in
epitaxial Cu/Ni90Fe10/Cu/Si(001) films.
M. Ciria, R. C. O'Handley.
J. Magn. Magn. Mat. 2002, 240, 464-466.
Magnetism in polyoxometalates: anisotropic
II
exchange interactions in the Co 3 moiety of
12[Co3W(D2O)2(ZnW9O34)2] . A magnetic and
inelastic neutron scattering study.
J. M. Clemente, E. Coronado, A. Gaita-Ariño, C.
Giménez-Saiz, G. Chaboussant, H. U. Güdel, R.
Burriel, H. Mutka.
Chem. Eur. J. 2002, 8, 5701-5708.
Do aurophilic interactions complete against
hydrogen bonds? Experimental evidence and
rationalization
based
on
ab
initio
calculations.
A. Codina, E. J. Fernández, P. G. Jones, A.
Laguna, J. M. López de Luzuriaga, M. Monge,
M. E. Olmos, J. Pérez, M. A. Rodríguez.
J. Am. Chem. Soc. 2002, 122, 6781-6786.
Architecture dependence on the steric
constrains of the ligand in cyano-bridged
copper(I) and copper(II)-copper(I) mixedvalence polymer compounds containing
diamines:
Crystal
structures
and
spectroscopic and magnetic properties.
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Rare earth effects on the magnetic behavior
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Structure and exchange in silicon-linked
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Spin glass and noninteracting nanoparticle
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The unexpected synthesis of rhodium(I)
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Heterodinuclear
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Experimental and theoretical study of the 1,3dipolar
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Trans additions of silanes to 1-alkynes
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Microstructure-size dependence of the 1.520
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Physica C 2002, 372, 1179-1182.
Magnetostriction effects.
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Preparation
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Desalination 2002, 147, 425-431.
Correlation of normal and superconducting
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E. Natividad, M. Castro, R. Burriel, L. A. Angurel,
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Supercond. Sci. Tech. 2002, 15, 1022-1029.
Enhancement of the 77 K critical currents on
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Physica C 2002, 372, 1055-1058.
Influence of the post-annealing cooling rate
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E. Natividad, J. A. Gómez, L. A. Angurel, A.
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Radial changes in the microstructure of LFZtextured Bi-2212 thin rods induced by
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Physica C 2002, 383, 379-387.
Synthesis and characterization of a wholly
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A. Negredo, F. Navarro.
Liq. Cryst. 2002, 29, 1-8.
Piezo-spectroscopy at low temperatures:
residual
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V. M. Orera, R. Cemborain, R. I. Merino, J. I.
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Synthesis and properties of push-pull
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Two-Dimensional
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E. Palacios Lidón, E. Palacios, R. Burriel, A.
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Spectroscopic propierties of Er3+ and Nd3+
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Determination of the next nearest neighbors
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Magnetic properties of RFe11.3W0.7 0 (R= Dy,
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A new family of conjugated metallopolymers
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Growth of large La2-xSrxNiO4+δ single crystals
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Design of a sature anchor based on the
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J. A. Puértolas, J. M. Pérez García, E. Juan, R.
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Characterization of trace Nd and Ce site
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S. Quartieri, F. Boscherini, J. Chaboy, M. C.
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Phys. Chem. Miner. 2002, 29, 495-502.
Synthesis, characterization and crystal
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complexes
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Polyhedron 2002, 21, 1023-1030.
Fatigue damage on composite materials.
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Magnetic and structural phase diagram of
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Phys. Rev. B 2002, 65, Art. Nº 094405.
Crystal and magnetic structures of La2MTiO6
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High Pressure Res. 2002, 22, 115-119.
Study of zircon-dolomite reactions monitored
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Solvent controlled nuclearity in Cu(II)
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Synthesis, structure and magnetic-properties
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Thermal stability of Pt/Al2O3 catalyst
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Light-induced orientation of dyes in
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R. Rosenhauer, T. Fisher, J. Stumpe, R.
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Proc. Of Spie 2002, 4799, 121-135.
First synthesis of the two enantiomers of αmethyldiphenylalanine [(αMe)Dip] by HPLC
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Chirality 2002,14, 39-46.
X-ray Raman scattering from the carbon K
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J. P. Rueff, Y. Yoly, F. Bartolomé, M. Krisch, J.
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Eur. J. Inorg. Chem. 2002, 1071-1075.
Geometric coercivity scaling in magnetic thin
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I. Ruiz-Feal, L. López-Díaz, A. Hirohata, J.
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Polarised temperature dependent xanes
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X-ray absorption study of LaNi1-xMnxO3+δ
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M. C. Sánchez, J. García, J. Blasco, G. Subías,
J. Pérez-Cacho.
E.S.R.F. Highlights 2002, 40-41.
Local electronic and geometrical structure of
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La(Ni1-xMnx)O3+y
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M. C. Sánchez, J. García, J. Blasco, G. Subías,
J. Pérez-Cacho.
Phys. Rev. B 2002, 65, Art. Nº 144409.
Raman study of Zn1-xMnxGa2Se4 diluted
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M. L. Sanjuán, M. C. Morón.
Physica B 2002, 316-317, 565-567.
Oxide thin film deposition on eutectic
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J. Santiso, V. Laukhin, G. García, A. Figueras, L.
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Thin Solid Films 2002, 405, 87-91.
Coupling of arylamines with coordinated
arylazopyrimidines
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P. K. Santra, P. Byabartta, S. Chattopadhyay, L.
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Eur. J. Inorg. Chem. 2002, 1124-1131.
Large low-field magnetoresistance and TC in
polycrystalline
(Ba0.8Sr0.2)2-xLaxFeMoO6
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D. Serrate, J. M. de Teresa, J. Blasco, M. R.
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Exchange and crystal field in Sm-based
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high-field magnetization study of Sm2Fe17
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L. J. Sippel, M. Loewenhaupt, D. Eckert, P.
Kerschl, A. Handstein, K. H. Müller, M. Wolf, M.
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Phys. Rev. B 2002, 65, Art. Nº 064408.
Thermopower
behaviour
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the
Gd5(Si0.1Ge0.9)4 magnetocaloric coumpound
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Spin disorder scattering in magnetic metallic
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J. Stankiewicz, J. Bartolomé, D. Fruchart.
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Mn-local structure effects in charge-ordered
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mixed-valence
RE1-xCaxMnO3
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G. Subías, J. García, J. Blasco, M. C. Sánchez,
M. G. Proietti.
J. Phys. Condens. Mat. 2002, 14, 5017-5033.
Soft X-ray absorption spectroscopy (Mn L2,3
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G. Subías, J. García, M. C. Sánchez, J. Blasco,
M. G. Proietti.
Surf. Rev. Lett. 2002, 9, 1071-1078.
Dinuclear rhodium and iridium complexes
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amido/methoxo
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C. Tejel, M. A. Ciriano, M. Bordonaba, J. A.
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Structural and dynamic studies on amidobridged rhodium and iridium complexes.
C. Tejel, M. A. Ciriano, M. Bordonaba, J. A.
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Chem. Eur. J. 2002, 8, 3128-3138.
Magnetic versus orbital polarons in colossal
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J. M. de Teresa, M. R. Ibarra, P. A. Algarabel, L.
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Phys. Rev. B 2002, 65, 100403.
Aplicación de redes neuronales a la
predicción de congestiones de tráfico.
N. Tolosana, L. Castejón, A. Miravete, J.
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CIT 2002, 1353-1360.
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The superstructure of C3S from shynchrotron
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A. de la Torre, S. Bruque, J. Campo, A. Miguel,
G. Aranda.
Cement Concret Res. 2002, 2070, 1-10.
Magnetic
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of
granular
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J. M. Torres, F. Luis,
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J. Magn. Magn. Mat., 2002, 242-245, 575-577.
Interactions between Josephson vortices
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E. Trías, J. J. Mazo, T. P. Orlando.
Phys. Rev. B 2002, 65, 054517.
Synthesis of group 10 polyfluorothiolate
mono- and binuclear complexes. Crystal
structures
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[Ni(SC6HF4)2(dppe)]Ni(µSC6HF4)2Pd(C6F5)2]
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M. A. Usón, J. M. Llanos.
J. Organomet. Chem. 2002, 663, 98-107.
Magnetovolume
effects
of
Y-Fe-Co-Ti
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J. L. Wang, M. R. Ibarra, C. Marquina, B. García
Landa, O. Tegus, Q. F. Xiao, E. Brück, F. M.
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J. Appl. Phys. 2002, 91, 8216-8218.
Effect of Mn substitution on volume and
magnetic properties of Er2Fe17.
J. L. Wang, M. R. Ibarra, C. Marquina, B. García
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Magnetovolume effect in ThMn12-type Fe-rich
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J. L. Wang, C. Marquina, B. García Landa, M. R.
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Physica B 2002, 319, 73-77.
Sequential C-H activation and dinuclear
insertion of ethylene promoted by a diiridium
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Y. F. Yuan, M. V. Jiménez, E. Sola, F. J. Lahoz,
L. A. Oro.
J. Am. Chem. Soc. 2002,124, 752-753.
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Molecular nitrides containing group 4 and 5
metals. Single and double azatitanocubanes.
A. Abarca, M. V. Galakhov, J. Gracia, A. Martín,
M. Mena, J. M. Poblet, J. P. Sarasa, C.
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Chem. Eur. J. 2003, 9, 2337-2346.
Synthesis and structure of new carboranesubstituted cyclotriphosphazenes.
D. Abizanda, O. Crespo, M. C. Gimeno, J.
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Chem. Eur. J. 2003, 9, 3310-3319.
Structural modifications and fibre processing
of
hydroxy-functionalised
mesogenic
polyazomethines.
J. M. Adell, M. P. Alonso, J. Barberá, L. Oriol, M.
Piñol, J. L. Serrano.
Polymer 2003, 44, 7829-7841.
A thiazyl-based organic ferromagnet.
A. Alberola, R. J. Less, C. M. Pask, J. M.
Rawson, F. Palacio, P. Oliete, C. Paulsen, A.
Yamaguchi, R. D. Farley, D. M. Murphy.
Angew. Chem. Int. Edit. 2003, 42, 4782-4785.
Peculiar ferromagnetic insulator state in the
low-hole-doped manganites.
P. A. Algarabel, J. M. de Teresa, J. Blasco, M.
R. Ibarra, C. Kapusta, M. Sikora, D. Zajac, P. C.
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Phys. Rev. B 2003, 67, Art. Nº 134402.
Reactivity
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[NBu4][(C6F5)2M(µPPh2)2M'(acac-O,O')] (M, M ' = Pt, Pd) toward
silver centers. Synthesis of polynuclear
complexes containing M-Ag bonds (M =
Pd,Pt).
E. Alonso, J. Forniés, C. Fortuño, A. Martín, A.
G. Orpen.
Organometallics 2003, 22, 5011-5019.
Synthesis of neutral and anionic tetranuclear
2
3
clusters [Pt4(µ(2)-PPh2)3{µ3-PPh(1,2-η -Ph)-κ
P}(C6F5)4L]
and
[NBu4][Pt4(µ2-PPh2)3{µ32
3
PPh(1,2-η -Ph)- κ P}(C6F5)5] containing five
coordinate P atoms and two Pt-Pt bonds.
E. Alonso, J. Forniés, C. Fortuño, A. Martín, A.
G. Orpen.
Organometallics 2003, 22, 2723-2728.
Formation of a cyclobutylidene ring,
intramolecular [2+2] cycloaddition of allyl
and vinylidene C=C bonds under mild
conditions.
P. Álvarez, E. Lastra, J. Gimeno, M. Bassetti, L.
R. Falvello.
J. Am. Chem. Soc. 2003, 125, 2386-2387.
Structural and magnetic properties of a novel
ferrocenyl-diiodine charge transfer complex.
D. W. Allen, R. Berridge, N. Bricklebank, S. D.
Forder, F. Palacio, S. J. Coles, M. B.
Hursthouse, P. J. Skabara.
Inorg. Chem. 2003, 42, 3975-3977.
Tricritical points in La-based ferromagnetic
manganites.
V. S. Amaral, J. P. Araujo, Y. G. Pogorelov, J. B.
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Algarabel, M. R. Ibarra.
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Novel NLO-phores with proaromatic donor
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R. Andreu, J. Garín, J. Orduna, R. Alcalá, B.
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Effects of Ti addition on LFZ Bi-2212 thin
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L. A. Angurel, M. Mora, J. C. Díez, R. J. Drost,
P. H. Kes.
Bol. Soc. Esp. Ceram. V 2003, 42, 157-162.
Synthesis, structures and photophysics of
novel
luminescent
platinum-copper
complexes.
I. Ara, J. R. Berenguer, E. Eguizábal, J. Forniés,
J. Gómez, E. Lalinde.
J. Organomet. Chem. 2003, 670, 221-234.
Polymeric (O-ethyl dithiocarbonato)silver(I).
I. Ara, F. El Bahij, M. Lachkar.
Acta Crystallogr. C 2003, 59, M265-M267.
Synthesis
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characterization
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ethylxanthato complexes of zinc(II) with Pdonor ligands.
I. Ara, F. El Bahij, M. Lachkar, N. Ben Larbi.
Transit. Metal. Chem. 2003, 28, 908-912.
2
S,S')
Bis
(O-ethyl
dithiocarbonato-κ
palladium (II).
I. Ara, F. El Bahij, M. Lachkar, N. Ben Larbi.
Acta Crystallogr. C 2003, 59, M199-M200.
A
new
polymorph
of
(O-ethyl
dithiocarbonatoκ2
S,S')
bis
(triphenylphosphine- κ P)silver(I).
I. Ara, F. El Bahij, M. Lachkar, N. Ben Larbi.
Acta Crystallogr. C 2003, 59, M107-M108.
New Pt-Hg clusters with pentachlorophenyl
groups.
I. Ara, J. Forniés, L. Gabilondo, M. A. Usón.
Inorg. Chim. Acta 2003, 347, 155-160.
Synthesis and characterization of new fivecoordinate platinum nitrosyl derivatives,
Density functional theory study of their
electronic structure.
I. Ara, J. Forniés, M. A. Garcia-Monforte, B.
Menjón, R. M. Sanz-Carrillo, M. Tomás, A. C.
Tsipis, C. A. Tsipis.
Chem. Eur. J. 2003, 9, 4094-4105.
Synthesis
of
new
anionic
perhalophenylplatinate(II) complexes.
I. Ara, J. Forniés, S. Ramos, M. Tomás.
Syn. React. Inorg. Mat. 2003, 33, 1723-1739.
Synthesis and characterisation of new
binuclear complexes containing a relatively
strong Pt to Hg donor bond. Molecular
structure
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complex
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I. Ara, J. Forniés, V. Sicilia, P. Villarroya.
J. Chem. Soc. Dalton 2003, 22, 4238-4242.
Order-disorder transitions and magnetic
behaviour in lithium ferrites
Li0.5+0.5xFe2.5-1.5xTixO4 (x=1.28 and 1.50).
M. A. Arillo, M. L. López, C. Pico, M. L. Veiga, J.
Campo, J. L. Martínez, A. Santrich-Badal.
Eur. J. Inorg. Chem. 2003, 13, 2397-2405.
Structural properties and stability of
metastable phases in the Zr-Nb system, part
II. Aging of Bcc (beta) alloys and assessment
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G. Aurelio, A. F. Guillermet, G. J. Cuello, J.
Campo.
Metall. Mater. Trans. A 2003, 34, 2771-2779.
Synthesis of enantiopure (αMe)Dip and other
α-methylated
β-branched
amino
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A. Avenoza, J. H. Busto, C. Cativiela, J. M.
Peregrina, D. Sucunza, M. M. Zurbano.
Tetrahedron: Asymmetry 2003, 14, 399-405.
The critical state in type-II superconductors
with cross-flow effects.
A. Badía, C. López.
J. Low. Temp. Phys. 2003, 130, 129-153.
Study
of
the
reactions
between
vinylmagnesium bromide and imines derived
from (R)-glyceraldehyde - The key step in the
stereodivergent synthesis of conveniently
protected, enantiopure syn- and anti-2amino-1,3,4-butanetriol derivatives.
R. Badorrey, C. Cativiela, M. D. Díaz de
Villegas, R. Díez, J. A. Gálvez.
Eur. J. Org. Chem. 2003, 12, 2268-2275.
Study of the Lewis acid-promoted imines
derived from addition of silylenol ethers to
glyceraldehyde.
R. Badorrey, C. Cativiela, M. D. Díaz-deVillegas, J. A. Gálvez.
Tetrahedron Lett. 2003, 44, 9189-9192.
Efficient resolution of rac-2-cyano-2-methyl3-phenylpropanoic acid. An appropriate
starting material for the enantioconvergent
synthesis of (S)-α-methylphenylalanine on a
large laboratory scale.
R. Badorrey, C. Cativiela, M. D. Díaz de
Villegas, J. A. Gálvez.
Tetrahedron: Asymmetry 2003, 14, 2201-2207.
Efficient enantioconvergent synthesis of (S)α-benzyl-α-methyl-β-alanine from (R)- and
(S)-2-cyano-2-methyl-3-phenylpropanoic
acid.
R. Badorrey, C. Cativiela, M. D. Díaz-deVillegas, J. A. Gálvez, A. Gil.
Tetrahedron: Asymmetry 2003, 14, 2209-2214.
Supramolecular
helical
stacking
of
metallomesogens derived from enantiopure
and racemic polycatenar oxazolines.
J. Barberá, E. Cavero, M. Lehmann, J. L.
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J. Am. Chem. Soc. 2003, 125, 4527-4533.
182
Bis(salicylaldiminate)
copper(II)
and
palladium(II) complexes, towards columnar
mesophases.
J. Barberá, R. Giménez, N. Gimeno, M. Marcos,
M. D. Pina, J. L. Serrano.
Liq. Cryst. 2003, 30, 651-661.
Paramagnetic bimetallomesogens.
J. Barberá, R. Giménez, M. Marcos, J. L.
Serrano, P. J. Alonso, J. I. Martínez.
Chem. Mater. 2003, 15, 958-964.
Synthesis and structural characterization of
luminescent gold(I) derivatives with an
unsymmetric diphosphine.
M. Bardají, P. G. Jones, A. Laguna, M. D.
Villacampa, N. Villaverde.
J. Chem. Soc. Dalton 2003, 23, 4529-4536.
Heteronuclear metal-metal contacts between
gold(I) and group-11,-12, and-13 centers.
M. Bardají, A. Laguna.
Eur. J. Inorg. Chem. 2003, 17, 3069-3079.
Reactions of elongated dihydrogen-osmium
complexes
containing
orthometalated
ketones with alkynes, hydride-vinylidene-πalkyne versus hydride-osmacyclopropene.
P. Barrio, M. A. Esteruelas, E. Oñate.
Organometallics 2003, 22, 2472-2485.
Magnetic relaxation phenomena in R2Fe17
(R=Y, Dy, Er, Ho) and C and H derivatives.
J. Bartolomé, S. Mukherjee, C. Rillo, N. Plugaru,
C. Piquer.
J. Alloy Compd. 2003, 356, 208-210.
Coordination complexes of a silicon-linked
organic tetranitroxide.
M. Baskett, P. M. Lahti, F. Palacio.
Polyhedron 2003, 22, 2363-2374.
Memory of chirality in the stereoselective
synthesis of β-lactams, importance of the
starting amino acid derivative.
M. A. Bonache, G. Gerona Navarro, C. García
Aparicio, M. Alias, M. Martín Martínez, M. T.
García López, P. López, C. Cativiela, R.
González Muñíz
Tetrahedron: Asymmetry 2003, 14, 2161-2169.
Memory of chirality in the enantioselective
synthesis of β-lactams derived from amino
acids. Influence of the reaction conditions
M. A. Bonache, G. Gerona Navarro, M. Martín
Martínez, M. T. García López, P. López, C.
Cativiela, R. González Muñíz
Synlett. 2003, 7, 1007-1011.
Magnetic
coupling
in
epitaxial
TM/MgO/Fe(001) (TM = FeCo, Fe/Co, Fe)
macroscopic and microscopic trilayers.
C. M. Boubeta, J. M. de Teresa, J. L. CostaKramer, J. Anguita, D. Serrate, J. I. Arnaudas,
M. R. Ibarra, A. Cebollada, F. Briones.
J. Appl. Phys. 2003, 94, 4006-4012.
P-31 NMR spectroscopy as a powerful tool
for the determination of enantiomeric excess
and absolute configurations of alpha-amino
acids.
J. Bravo, C. Cativiela, J. E. Chaves, R. Navarro,
E. P. Urriolabeitia.
Inorg. Chem. 2003, 42, 1006-1013.
Wavelength de-multiplexing properties of a
single aperture flanked by periodic arrays of
indentations.
J. Bravo-Abad, F. J. García Vidal, L. Martín
Moreno.
Photonics And Nanostructures, 2003, 55.
Synthesis,
characterization
and
luminescence properties of homoleptic
platinum(II) acetylide complexes.
J. Benito, J. R. Berenguer, J. Forniés, B. Gil, J.
Gómez, E. Lalinde.
J. Chem. Soc. Dalton 2003, 22, 4331-4339.
Enantioselective catalysis; 150, Chiral-at6
metal (η -p-cymene)ruthenium(II) complexes
of
binaphthyl
ligands.
Synthesis,
characterization,
and
enantioselective
catalysis.
H. Brunner, F. Henning, M. Weber, M. Zabel, D.
Carmona, F. J. Lahoz.
Synthesis 2003, 7, 1091-1099.
Predimensionado de palas aerogeneradores
de gran tamaño mediante un método de
cálculo
por
secciones
y
algoritmos
genéticos. Aplicación a una pala de 6 MW.
E. Bernal, J. Cuartero, C. Nuez, A. Miravete, J.
C. Román, G. Hauke, M. García.
Materiales Compuestos, 2003, 441-451.
Preparation and characterization of 4azoniaheptatrienyl,
4-azaheptatrienyl,
ruthenapyrrolinone,
and
pyrrolinyl
complexes of ruthenium.
M. L. Buil, M. A. Esteruelas, A. M. López, E.
Oñate.
Organometallics 2003, 22, 5274-5284.
Degradation mechanism of an acrylic waterbased paint applied to steels.
M. Bethencourt, F. J. Botana, M. J. Cano, R. M.
Osuna, M. Marcos.
Prog. Org. Coat. 2003, 47, 164-168.
C-N and C-C coupling reactions, Preparation
of new N-heterocyclic ruthenium derivatives.
M. L. Buil, M. A. Esteruelas, A. M. López, E.
Oñate.
Organometallics 2003, 22, 162-171.
Effects of Ga doping in La2/3Sr1/3MnO3.
J. Blasco, J. García, J. Stankiewicz.
Phys. Rev. B 2003, 68, Art. No. 054421.
183
Gold, silver and palladium complexes with
the 2,2'-dipyridylamine ligand.
M. Burgos, O. Crespo, M. C. Gimeno, P. G.
Jones, A. Laguna.
Eur. J. Inorg. Chem. 2003, 11, 2170-2174.
Improvement of ligand economy controlled
by polymer morphology. The case of
polymer-supported bis(oxazoline) catalysts.
M. I. Burguete, E. Díez Barra, J. M. Fraile, J. I.
García, E. García Verdugo, R. González, C.
Herrerías, S. V. Luis, J. A. Mayoral, P. Sánchez
Verdú.
Bioorg. Med. Chem. Lett. 2003, 13, 151.
Effect of spin delocalisation in K2FeC15
center dot H2O on its superexchange
pathways.
J. Campo, J. Luzón, F. Palacio, G. J. McIntyre,
E. Ressouche.
Physica B 2003, 335, 15-18.
Superexchange
interaction
enhanced
through spin delocalisation in Rb2FeBr5
center dot H2O as studied by polarised
neutron diffraction.
J. Campo, J. Luzón, F. B. Palacio, A. Millán, G.
J. McIntyre.
Polyhedron 2003, 22, 2297-2299.
Gold and silver derivatives with the
carborane-selenolate ligand [B10H11C2Se] .
S. Canales, O. Crespo, M. C. Gimeno, P. G.
Jones, A. Laguna, P. Romero.
J. Chem. Soc. Dalton 2003, 23, 4525-4528.
Gold and silver complexes with the
diselenium ligand [Ph2P(Se)NP(Se)Ph2] .
S. Canales, O. Crespo, M. C. Gimeno, P. G.
Jones, A. Silvestru, C. Silvestru.
Inorg. Chim. Acta 2003, 347, 16-22.
Synthesis, molecular structure, and reactivity
of iridium(I) and iridium(III) complexes
formed by coordination and C-H activation of
i
the substituted arenes C6H5CH2CH2P Pr2 and
t
C6H5OCH2CH2P Bu2.
G. Canepa, E. Sola, M. Martín, F. J. Lahoz, L. A.
Oro, H. Werner.
Organometallics 2003, 22, 2151-2160.
Fatigue analysis of a semi-trailer axle
support by means of F.E.M. and application
of elastic-plastic models for welding joints
and thermally affected zones.
M. Carrera, L. Castejón, C. Martín, D. Ranz, A.
Miravete, J. Cuartero, E. Larrodé.
Comput. Plast. 2003, 244.
Stereoselective
oxidative
additions
of
iodoalkanes and activated alkynes to a
sulfido-bridged heterotrinuclear early-late
(Tilr2) complex.
M. A. Casado, J. J. Pérez Torrente, M. A.
Ciriano, I. T. Dobrinovitch, F. J. Lahoz, L. A. Oro.
Inorg. Chem. 2003, 42, 3956-3964.
Organometallic gold(III) compounds as
catalysts for the addition of water and
methanol to terminal alkynes.
R. Casado, M. Contel, M. Laguna, P. Romero,
S. Sanz.
J. Am. Chem. Soc. 2003, 125, 11925-11935.
N-acetyl-N'-methylamide
derivative
of
(2S,3S)-1-amino-2,3-diphenylcyclopropanecarboxylic acid. Theoretical analysis of the
conformational impact produced by the
incorporation of the second phenyl group to
the cyclopropane analogue of phenylalanine.
J. Casanovas, A. I. Jiménez, C. Cativiela, J. J.
Pérez, C. Alemán.
J. Org. Chem. 2003, 68, 7088-7091.
Composition and microstructure changes of
cement pastes when heating until high
temperature monitored by in situ neutron
diffraction.
M. Castellote, X. Turrillas, M. C. Alonso, M. C.
Andrade, J. Campo.
Cements Concret. Res. 2003.
Dynamic heat capacity in the relaxation
process of poly(vinyl acetate) at low
frequency.
M. Castro, J. A. Puértolas.
Thermochim. Acta 2003, 402, 159-168.
Heterogeneous catalysis in the synthesis
and reactivity of allantoin.
C. Cativiela, J. M. Fraile, J. I. García, B. Lázaro,
J. A. Mayoral, A. Pallarés.
Green Chem. 2003, 5, 275-277.
Magnetoelastic coupling in thin films with
weak out-of-plane anisotropy.
M. Ciria, J. I. Arnaudas, L. Benito, C. de la
Fuente, A. del Moral, J. K. Ha, R. C. O'Handley.
Phys. Rev. B 2003, 67, Art. No. 024429.
Structural
complexes
characterization
of
silver(I)
of diphenylmethanimine and
(diphenylmethyleneamino)diphenylphosphine.
A. Codina, O. Crespo, E. J. Fernández, P. G.
Jones, A. Laguna, J. M. López de Luzuriaga, M.
E. Olmos.
Inorg. Chim. Acta 2003, 347, 9-15.
Fluorous biphasic catalysis, Synthesis and
characterization of copper(I) and copper(II)
fluoroponytailed 1,4,7-R-f-TACN and 2,2'-R-fbipyridine complexes - Their catalytic activity
in the oxidation of hydrocarbons, olefins,
and
alcohols,
including
mechanistic
implications.
M. Contel, C. Izuel, M. Laguna, P. R. Villuendas,
P. J. Alonso, R. H. Fish.
Chem. Eur. J. 2003, 9, 4168-4178.
184
Surface-mediated
improvement
of
enantioselectivity
with
clay-immobilized
copper catalysts.
A. Cornejo, J. M. Fraile, J. I. García, M. J. Gil, C.
Herrerías, G. Legarreta, V. Martínez Merino, J.
A. Mayoral.
J. Mol. Catal. A-Chem. 2003, 196, 101-108.
Highlights in the field of molecule-based
magnets and other magnetic molecular
materials.
E. Coronado, F. Palacio, J. Veciana.
Angew. Chem. Int. Ed. 2003, 42, 2570-2572.
Highlights of this international conference on
the science, technology and industrial
applications of gold.
M. Cortie, R. Holliday, A. Laguna, G. J.
Nieuwenhuys, D. Thompson.
Gold Bull. 2003, 36, 144-151.
3D
modeling
of
coupling
between
superconducting filaments via resistive
matrix in ac magnetic field.
M. Costa, E. Martínez, C. Beduz, Y. Yang, F.
Grilli, B. Dutoit, E. Vinot, P. Tixador.
IEEE T. Appl. Supercon. 2003, 13, 3634-3637.
Coordination
modes
of
diphenylphosphinothioformamide
in
its
neutral and deprotonated forms at gold(I).
O. Crespo, E. J. Fernández, P. G. Jones, A.
Laguna, J. M. López de Luzuriaga, M. Monge,
M. E. Olmos, J. Pérez.
J. Chem. Soc. Dalton 2003, 6, 1076-1082.
Luminescent
nido-carborane-diphosphine
i
anions [(PR2)2C2B9H10] (R = Ph, Pr).
Modification of their luminescence properties
upon formation of three-coordinate gold(I)
complexes.
O. Crespo, M. C. Gimeno, P. G. Jones, A.
Laguna, J. M. López de Luzuriaga, M. Monge,
M. E. Olmos, J. Pérez, M. A. Ramón.
Inorg. Chem. 2003, 42, 2061-2068.
Recipientes a presión en materiales
compuestos: Una alternativa para el
almacenamiento de GNV.
J. Cruz, A. Miravete, A. Chiminelli, G. Vargas.
Corrosión y Protección, 2003.
Ensayo AMOCO de “blistering” sobre
laminados protegidos con gel coat.
J. Cuartero, O. Lacámara, A. Miravete, A.
Alonso, L. Castejón.
Materiales Compuestos, 2003, 43-51.
Propuesta
de
determinación
de
las
propiedades fuera del plano en laminados no
homogéneos.
J. Cuartero, A. Miravete, O. Lacámara, A.
Alonso, M. Carrera, E. Bernal.
Materiales Compuestos, 2003, 315-322.
Relationship between hydriding and Nd
magnetic moment in Nd2Fe14B.
J. Chaboy, C. Piquer, N. Plugaru, M. Artigas, H.
Maruyama, N. Kawamura, M. Suzuki.
J. Appl. Phys. 2003, 93, 475-478.
Enhancement of anisotropy in Nd2Fe14B
driven by Eu substitution.
J. Chaboy, N. Plugaru, J. Bartolomé, G. Subías.
Phys. Rev. B 2003, 67, Art. No. 014415.
Anion-directed structural diversity in the
complexes
of
Cd(II)-arylazoimidazole,
synthesis, spectral characterization and
crystal structure.
B. G. Chand, U. S. Ray, G. Mostafa, T. H. Lu L.
R. Falvello, T. Soler, M. Tomas, C. Sinha.
Polyhedron 2003, 22, 3161-3169.
Phototunable lasing in dye-doped cholesteric
liquid crystals.
A. Chanishvili, G. Chilaya, G. Petriashvili, R.
Barberi, R. Bartolino, G. Cipparrone, A.
Mazzulla, L. Oriol.
Appl. Phys. Lett., 2003, 83, 5353-5355.
Synthesis and electrical and optical
properties of [PtTl2-xLix(C6F5)2(C≡CPh)2]
(x=0, 1).
J. P. H. Charmant, J. Forniés, J. Gómez, E.
Lalinde, R. I. Merino, M. T. Moreno, A. G. Orpen.
Organometallics 2003, 22, 652-656.
Enantioselective
synthesis
of
N,Opsiconucleosides.
U. Chiacchio, L. Borrello, D. Iannazzo, P.
Merino, A. Piperno, A. Rescifina, B. Richichi, G.
Romeo.
Tetrahedron: Asymmetry 2003, 14, 2419-2425.
Isoxazolidine analogues of pseudouridine, a
new class of modified nucleosides.
U. Chiacchio, A. Corsaro, J. Mates, P. Merino,
A. Piperno, A. Rescifina, G. Romeo, R. Romeo,
T. Tejero.
Tetrahedron, 2003, 59, 4733-4738.
Thermoluminescence properties of
CaF2-LiF,Mn eutectic melt grown composites.
A. Chouiyakh, F. Gimeno, J. I. Peña, L.
Contreras, V. M. Orera.
Phys. Chem. News, 2003, 13, 139-143.
Polymer immobilization of bis(oxazoline)
ligands using dendrimers as cross-linkers.
E. Díez Barra, J. M. Fraile, J. I. García, E.
García Verdugo, C. Herrerías, S. V. Luis, J. A.
Mayoral, P. Sánchez Verdú, J. Tolosa.
Tetrahedron Asymmetry 2003, 14, 773-778.
The effect of high electric fields on the
structure and dielectric properties of the B-2
phase.
S. Díez, M. R. de la Fuente, M. A. P. Jubindo, B.
Ros.
Liq. Cryst. 2003, 30, 1407-1412.
185
D-d exchange interactions in narrow-gap
diluted magnetic semiconductors. The case
of Hg1-xCoxS.
K. Dybko, W. Szuszkiewicz, E. Dynowska, F.
Palacio.
Phys. Rev. B 2003, 68, Art. No. 092411.
Bioorganometallic chemistry - Part 15. A
novel molecular recognition process of host,
trans-[Cp*Rh(η1(N3)-1-methylcytosine)
(µOH)]2 (OTf)2,with L-aromatic amino acid
guests, selective hydrogen bonding to the µOH groups and the 1-methylcytosine ligands.
A. Elduque, D. Carmona, L. A. Oro, M.
Eisenstein, R. H. Fish.
J. Organomet. Chem. 2003, 668, 123-127.
Stabilization of a chelate tautomer of
phenylacetylide.
M. A. Esteruelas, F. J. Fernández, A. M. López,
E. Oñate.
Organometallics 2003, 22, 1787-1789.
An osmium-carbene complex with FischerSchrock ambivalent behavior.
M. A. Esteruelas, A. I. González, A. M. López, E.
Oñate.
Organometallics 2003, 22, 414-425.
Preparation,
structure,
and
ethylene
polymerization behavior of bis(imino)pyridyl
chromium(III) complexes.
M. A. Esteruelas, A. M. López, L. Méndez, M.
Oliván, E. Oñate.
Organometallics 2003, 22, 395-406.
Preparation and characterization of osmium4 2
stannyl polyhydrides, d -d oxidative addition
of neutral molecules in a late transition
metal.
M. A. Esteruelas, A. Lledós, F. Maseras, M.
Oliván, E. Oñate, M. A. Tajada, J. Tomás.
Organometallics 2003, 22, 2087-2096
Ortho-CH activation of aromatic ketones,
partially fluorinated aromatic ketones, and
aromatic imines by a trihydride-stannylosmium(IV) complex.
M. A. Esteruelas, A. Lledós, M. Oliván, E. Oñate,
M. A. Tajada, G. Ujaque.
Organometallics, 2003, 22, 3753-3765.
Dioxygen activation by an osmium-dihydride,
4
Preparation and characterization of a d
square-planar complex.
M. A. Esteruelas, F. J. Modrego, E. Oñate, E.
Royo.
J. Am. Chem. Soc. 2003, 125, 13344-13345.
Induction of ferroelectricity in the B2 phase of
a liquid crystal composed of achiral bentcore molecules.
J. Etxebarria, C. L. Folcia, J. Ortega, M. R. Ros.
Phys. Rev. E 2003, 67, Art. No. 042702.
Magnetic and thermal properties of 4f-3d
ladder-type molecular compounds.
M. Evangelisti, M. L. Kahn, J. Bartolomé, L. J. de
Jongh, C. Meyers, J. Leandri, Y. Leroyer, C.
Mathoniere.
Phys. Rev. B 2003, 68, Art. No. 184405.
Through quantum tunneling to dipolar order,
the effect of varying magnetic anisotropy in
three structurally related Mn-4 molecular
clusters.
M. Evangelisti, F. Luis, F. L. Mettes, N. Aliaga,
G. Aromi, G. Christou, L. J. de Jongh.
Polyhedron 2003, 22, 2169-2173.
Física no lineal, solitones y caos.
F. Falo, R. Chacón, L. M. Floría.
Revista Española de Física 2003, 17, 19-23.
1Hexaaquanickel diorotate dihydrate at
150 K.
L. R. Falvello, D. Ferrer, T. Soler, M. Tomás.
Acta Crystallogr. C, 2003, 59, M149-M151.
Stabilized bis-ylides as a source of carbene
ligands in palladium(II) and platinum(II)
complexes.
L. R. Falvello, R. Llusar, M. E. Margalejo, R.
Navarro, E. P. Urriolabeitia.
Organometallics 2003, 22, 1132-1144.
Synthesis and characterization of Pd-II
complexes containing cyclic bis-ylides.
L. R. Falvello, M. E. Margalejo, R. Navarro, E. P.
Urriolabeitia.
Inorg. Chim. Acta 2003, 347, 75-85.
Dichlorobis(imidazolidin-2-one-κO) zinc (II) at
150 K.
L. R. Falvello, E. M. Miqueleiz, T. Soler, M.
Tomás.
Acta Crystallogr. C 2003, 59, M442-M445.
Effect of supramolecular aggregation on
coordination in cobalt(II) complexes of 2imidazolidone.
L. R. Falvello, E. M. Miqueleiz, M. Tomás.
Indian. J. Chem. A 2003, 42, 2307-2315.
Solid state synthesis, structure and optical
limiting properties of seleno cuboidal
clusters [M3Se4X3(diphosphine)3]+ (M = Mo,
W; X = Cl, Br).
M. Felíz, R. Llusar, S. Uriel, C. Vicent, M. G.
Humphrey, N. T. Lucas, M. Samoc, B. LutherDavies.
Inorg. Chim. Acta 2003, 349, 69-77.
Theoretical and photoluminescence studies
on the d10-d2 Au-I-Tl-I interaction in extended
unsupported chains.
E. J. Fernández, A. Laguna, J. M. López de
Luzuriaga, F. Mendizábal, M. Monge, M. E.
Olmos, J. Pérez
Chem. Eur. J. 2003, 9, 456-465.
186
[{AuTl(C6Cl5)2(toluene)}2(dioxane)]. A striking
structure that leads to a blue luminescence.
E. J. Fernández, A. Laguna, J. M. López de
Luzuriaga, M. E. Olmos, J. Pérez .
Chem. Commun. 2003, 14, 1760-1761.
{Tl[Au(C6Cl5)2]}n. A vapochromic complex.
E. J. Fernández, , J. M. López de Luzuriaga, M.
Monge, M. E. Olmos, J. Pérez A. Laguna, A. A.
Mohamed, J. P. Fackler.
J. Am. Chem. Soc. 2003, 125, 2022-2023.
Magnetization process of single molecule
magnets at low temperatures.
J. F. Fernández, J. J. Alonso.
Phys. Rev. Lett. 2003, 91, Art. No. 047202 .
Synthesis, structural characterisation and
photophysics of anionic cyclometalated
bis(alkynyl)(benzo[h]quinolinate) platinate(II)
species.
S. Fernández, J. Forniés, B. Gil, J. Gómez, E.
Lalinde.
J. Chem. Soc. Dalton 2003, 5, 822-830.
Manganese(II)
and
copper(II)
hexafluoroacetylacetonate 1 , 1 complexes with 5(4-[N-tert-butyl-N-aminoxyl]phenyl)pyrimidine
Regiochemical parity analysis for exchange
behavior of complexes between radicals and
paramagnetic cations.
L. M. Field, P. M. Lahti, F. Palacio, A. Paduan.
J. Am. Chem. Soc. 2003, 125, 10110-10118.
Low-temperature specific heat of the
Rb2KScF6 elpasolite.
I. N. Flerov, R. Burriel, M. V. Gorev, P. Isla, V. N.
Voronov.
Phys. Solid State 2003, 45, 167-170.
Synthesis and characterization of mono and
heteropolynuclear
luminescent
alkynyl
platinum
diphenylphosphinous
acid/phosphinite complexes.
J. Forniés, J. Gómez, E. Lalinde, M. T. Moreno.
Inorg. Chim. Acta 2003, 347, 145-154.
Professor Rafael Uson.
J. Forniés, A. Laguna.
Inorg. Chim. Acta 2003, 347, XIII-XIV.
Polynuclear palladium complexes with 3,5dimethylpyrazolate exhibiting three different
coordination modes.
J. Forniés, A. Martín, V. Sicilia, L. F. Martín.
Chem. Eur. J. 2003, 9, 3427-3435.
Cyclopropanation
of
olefins
with
heterogeneous catalysts - (Comment to the
paper ''Cyclopropanation of olefins using a
silica gel anchored palladium phosphine
complex'' by M. Lakshmi Kantam, Y. Haritha,
N. Mahender Reddy, B. M. Choudary, and F.
Figueras).
J. M. Fraile, J. I. García, J. A. Mayoral.
Catal. Lett. 2003, 88, 31-32.
Experimental and theoretical studies on
structure-reactivity relationships of titaniummodified silicas in the hydrogen peroxidepromoted oxidation of cyclohexene.
J. M. Fraile, J. I. García, J. A. Mayoral, L.
Salvatella, E. Vispe, D. R. Brown, G. Fuller.
J. Phys. Chem. B 2003, 107, 519-526.
Optimization of cyclohexene epoxidation
with dilute hydrogen peroxide and silicasupported titanium catalysts.
J. M. Fraile, J. I. García, J. A. Mayoral, E. Vispe.
Appl. Catal. A-Gen. 2003, 245, 363-376.
New silica-immobilized chiral amino alcohol
for
the
enantioselective
addition
of
diethylzinc to benzaldehyde.
J. M. Fraile, J. A. Mayoral, J. Serrano, M. A.
Pericas, L. Sola, D. Castellnou.
Org. Lett. 2003, 5, 4333-4335.
Effect of local molecular structure on the
chain-length dependence of the electronic
properties of thiophene-based π-conjugated
systems.
P. Frere, J. M. Raimundo, P. Blanchard, J.
Delaunay, P. Richomme, J. L. Sauvajol, J.
Orduna, J. Garín, J. Roncali.
J. Org. Chem. 2003, 68, 7254-7265.
Comment on "X-ray resonant scattering
studies of orbital and charge ordering in
Pr1-x CaxMnO3".
J. García, G. Subías.
Phys. Rev. B 2003, 68, Art. No. 127101.
HYSCORE spectroscopy in the cytochrome
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Focusing light with a single subwavelength
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Iterative organometallic addition to chiral
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Grazing incidence diffraction anomalous fine
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The Suzuki cross-coupling reaction,
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R. Guzmán de Villoria, A. Miravete, C. Nuez, M.
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Materiales Compuestos 2003, 243-250.
Estudio aerodinámico y selección de
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Materiales Compuestos 2003, 433-440.
Synthesis, reactivity, and catalytic activity of
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Cyclopropane analogue of valine: Influence
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Methylene- and diamidonaphthalene-bridged
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Inorg. Chim. Acta 2003, 350, 266-276.
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Grazing incidence diffraction anomalous fine
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Physica E 2003, 17, 541-542.
Método de obtención de la posición de
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M. Lizaranzu, J. Cuartero, A. Miravete, S. Anaya
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Oxidation state and localization of chromium
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Competitive effects of dipolar interactions
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Physica B 2003, 335, 1-5.
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Pressure-induced
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Versatility of cyclooctadiene ligands in
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Theory of highly directional emission from
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L. Martín Moreno, F. J. García Vidal, H. J.
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The rhodium and iridium co-ordination
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IEEE T. Appl. Supercon. 2003, 13, 3210-3213.
Polarised luminescent films containing
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Destructive
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E. Martínez, E. Natividad, L. A. Angurel, R.
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Physica C 2003, 385, 353-362.
Field-induced
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Dissipative discrete breathers: Periodic,
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P. J. Martínez, M. Meister, L. M. Floría, F. Falo.
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Discrete breathers in Josephson arrays.
J. J. Mazo, T. P. Orlando.
Chaos 2003, 13, 733-743.
Stereoselective synthesis of
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Long-range ferromagnetic dipolar ordering of
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1,3-dipolar cycloaddition between N-benzylC-glycosyl nitrones and methyl acrylate en
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Tetrahedron Asymmetry 2003, 14, 3731-3743.
Order-disorder phase transition in
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M. C. Morón, S. Hull
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A DFT study on the 1,3-dipolar cycloaddition
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Tetrahedron 2003, 59, 3581-3592.
Di-2-pyridylmethylamine-based
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An investigation of the Lewis acid mediated
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Radial changes in the microstructure of LFZtextured Bi-2212 thin rods induced by
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Physica C 2003, 383, 379-387.
A comparative study of the stereoselective
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Tetrahedron: Asymmetry 2003, 14, 367-379.
Met grown composite ceramics obtained by
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Cr. Chim. 2003, 6, 47-57.
Determination of the helical pitch in the
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Liq. Cryst. 2003, 30, 109-115.
Interpretation of unusual textures in the B2
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Phys. Rev. E 2003, 68, Art. No. 11707.
Nuclear polarization of Nd in the pseudo
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Phys. Rev. B 2003, 68, 224425.
The phases of [(CH3)4N](ClO4) at
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E. Palacios, R. Burriel, P. Ferloni.
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J. Am. Chem. Soc. 2003, 125, 9898-9899.
Folding of peptides characterized by c3Val, a
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Biopolymers 2003, 68, 178-191.
Ni and Co-ZrO2 composites produced by
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Ceramic Engeneering 2003, 24, 181-186.
The secret of early nanomaterials is revealed,
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J. Pérez Arantegui, A. Larrea.
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Neutron diffraction analysis of the order in a
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Lipopeptaibol metabolites of Tolypocladium
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Reinforced concrete beams strengthened for
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IEEE T. Instrum. Meas. 2003, 52, 621-625.
On the sensitivity of cryogenic current
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Metrologia 2003, 40, 51-56.
Photoluminescence
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Low-temperature structural and Raman
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Benito, M. A. Callejas, M. T. Martínez.
Nanotechnology 2003, 14, 184-187.
Protagonists in chemistry: Pierre Braunstein.
J. Rose, M. Knorr, L. A. Oro, A. Tiripicchio.
Inorg. Chim. Acta 2003, 350, XXVII-XXIX .
Chiral
codendrimers
derived
from
poly(propyleneimine) dendrimers (DAB).
J. L. Serrano, M. Marcos, R. Martín, M.
González, J. Barberá.
Chem. Mater. 2003, 15, 3866-3872.
Trapping of metastable high-spin species
and weak cooperativity in a mononuclear
Fe(II) spin-crossover system.
O. Roubeau, M. de Vos, A. F. Stassen, R.
Burriel, J. G. Haasnoot, J. Reedijk.
J. Phys. Chem. Solids 2003, 64, 1003-1013.
Helical supramolecular organizations from
metal-organic liquid crystals.
J. L. Serrano, T. Sierra.
Coordin. Chem. Rev. 2003, 242, 73-85.
Lamellar to columnar mesophase evolution
in a series of PAMAM liquid-crystalline
codendrimers.
J. M. Rueff, J. Barberá, B. Donnio, D. Guillon, M.
Marcos, J. L. Serrano.
Macromolecules 2003, 36, 8368-8375.
Diastereo- and enantioselective synthesis of
1'-C-branched N,O-nucleosides.
M. G. Saita, U. Chiacchio, D. Iannazzo, A.
Corsaro, P. Merino, A. Piperno, T. Previtera, A.
Rescifina, G. Romeo, R. Romeo.
Nucleos. Nucleot. Nucl. 2003, 22, 739-742.
Effect of thermal cycling on the strength and
superconducting properties of laser floating
zone textured Bi-2212 rods.
A. Salazar, J. Y. Pastor, J. Llorca, E. Natividad,
F. J. Gimeno, L. A. Angurel.
Physica C 2003, 384, 443-450.
Simplified calculus for the design of a
cryogenic current comparator.
J. Sesé, E. Bartolomé, A. Camón, J. Flokstra, G.
Rietveld, C. Rillo.
IEEE T. Instrum. Meas. 2003, 52, 612-616.
Magnetization reversal of individual Fe
nanowires in alumites studied by magnetic
force microscopy.
T. G. Sorop, C. Untiedt, F. Luis, L. J. de Jongh,
M. Kroll, M. Rasa.
J. Appl. Phys. 2003, 93, 7044-7046.
Magnetization reversal of ferromagnetic
nanowires studied by magnetic force
microscopy.
T. G. Sorop, C. Untiedt, F. Luis, M. Kroll, M.
Rasa, L. J. de Jongh.
Phys. Rev. B 2003, 67, Art. No. 014402.
192
Anomalous behavior of the electrical
resistivity in the giant magnetocaloric
compound Gd5(Si0.1Ge0.9)4.
J. B. Sousa, M. E. Braga, F. C. Correia, F.
Carpinteiro, L. Morellón, P. A. Algarabel, M. R.
Ibarra.
Phys. Rev. B 2003, 67, Art. No. 134416.
Trends in the design, manufacture and
evaluation of wind turbine blades.
P. S. Veers, T. D. Aschwill, H. J. Sutherlands, D.
L. Laird, D. W. Lobitz, D. A. Griffin, J. F. Mandell,
W. D. Musial, K. Jackson, M. Zuteck, A.
Miravete, S. W. Tsai, J. L. Richmond.
Wind Energy 2003, 6, 245-259.
Magnetic scattering in RMn12-xFex alloys.
J. Stankiewicz, J. Bartolomé, D. Fruchart.
Phys. Rev. B 2003, 67, Art. No. 092409.
Different kinetics of photoinactivation of
photosystem I-mediated electron transport
and P700 in isolated thylakoid membranes.
M. Velitchkova, I. Yruela, M. Alfonso, P. J.
Alonso, R. Picorel.
J. Photoch. Photobio. B 2003, 69, 41-48.
Stereospecific synthesis of trans-2,3-diaryl
substituted 1-aminocyclopropanecarboxylic
acid derivatives.
G. F. Su, H. T. Mu, D. M. Za, L. M. Zeng, C.
Cativiela, R. P. Hammer, K. B. Yu.
Synthetic. Commun. 2003, 33, 2873-2884.
Rhodium, iridium and gold complexes of the
short-bite
ligand
1-benzyl-2imidazolyldiphenylphosphine.
C. Tejel, M. A. Ciriano, R. Bravi R, L. A. Oro, C.
Graiff, R. Galassi, A. Burini.
Inorg. Chim. Acta 2003, 347, 129-136.
Protonation reactions of dinuclear pyrazolato
iridium(I) complexes.
C. Tejel, M. A. Ciriano, Millaruelo M, López JA,
F. J. Lahoz, L. A. Oro.
Inorg. Chem. 2003, 42, 4750-4758.
A hexanuclear iridium chain.
C. Tejel, M. A. Ciriano, B. E. Villarroya, J. A.
López, F. J. Lahoz, L. A. Oro.
Angew. Chem. Int. Edit. 2003, 42, 529-532.
Is the atmospheric pressure chemical
ionisation and collisionally induced methanol
loss from protonated dehydroamino acids a
retrosynthetic process?.
M. Tubaro, M. A. Fedrigo, C. Cativiela, A. I.
Jiménez, P. Traldi.
Rapid. Commun. Mass. Spectrom. 2003, 17,
107-113.
Mössbauer and magnetic evidence for spin
frustration in hetero-trinuclear clusters.
M. Vopsaroiu, V. Kuncser, J. Bartolomé, V. M.
Meriacre, K. I. Turta, I. Prisecaru, G. Filoti
Hyperfine Interact. 2003, 5, 213-216.
Spin
reorientation
and
crystal-field
interaction in TbFe12-xTix single crystals.
J. L. Wang, B. García Landa, C. Marquina, M. R.
Ibarra, F. M. Yang, G. H. Wu.
Phys. Rev. B 2003, 67, Art. No. 014417.
Synthesis, thermal expansion, and magnetic
properties of Gd3(Fe,Co,Cr)29 compounds.
J. L. Wang, C. Marquina, M. R. Ibarra, W. Q.
Wang, F. M. Yang, G. H. Wu, O. Tegus, J. C. P.
Klaasse, E. Bruck, F. R. de Boer.
J. Appl. Phys. 2003, 93, 6924-6926.
Detergent effect on cytochrome b559 electron
paramagnetic resonance signals in the
photosystem II reaction centre.
I. Yruela, I. García Rubio, M. Roncel, J. I.
Martínez, M. V. Ramiro, J. M. Ortega, P. J.
Alonso, R. Picorel.
Photoch. Photobio. Sci. 2003, 2, 437-442.
Influence of quenching treatments on
structure and conductivity of the
Li3xLa2/3-xTiO3 series.
A. Várez, J. Ibarra, A. Rivera, C. León, J.
Santamaría, M. A. Laguna, M. L. Sanjuán, J.
Sanz
Chem. Mater. 2003, 15, 225-232.
Influencia del cambio de ángulo de bobinado
sobre el comportamiento mecánico de los
domos de un depósito a presión en
materiales compuestos.
G. Vargas, J. Cruz, A. Miravete, A. Chiminelli.
Materiales Compuestos 2003, 353-361.
193
3.2.- Libros y Obras Colectivas
Books and Contributions to Compiled Works
E. Buñuel, A. I. Jiménez, M. D. Díaz de Villegas, C. Cativiela
“A chiral oxazolone derived from D-glyceraldehyde as an intermediate in the synthesis of
enantiomerically pure cyclic amino acids”. En Targets in Heterocyclic Systems. Chemistry and
Properties, vol. V.- Cambridge (Reino Unido): Royal Society of Chemistry, 2002.- Pp. 79-112.
J. Campo, J. Luzón, F. Palacio, G. J. McIntyre
“Superexchange interactions enhanced through spin delocalization in K2FeCl5.H2O”. En Highlight in
the year 2002 Annual Scientific Report of the ILL.- Pp. 18-19.
S. Domingo, S. Puértolas, F. Sánchez, L. Gracia Villa, J. A. Puértolas
“Aplicación de la superelasticidad del NiTi a los stents: Consideraciones termomecánicas”. En
Proc VIII Propiedades Mecánicas De Sólidos, 2002.- Pp. 417-424
F. Luis, F. L. Mettes, L. J. de Jongh
“Studies of quantum relaxation and coherence in molecular magnets by means of specific heat”.
En Magnetoscience: Molecules to material, vol III.- Weinheim: Wiley-VCH, 2002.- P. 169.
R. Lahoz, J. A. Puértolas
“Entrenamiento y memoria de forma de doble camino en aleaciones NiTi”. En VIII Prop. Mecánicas
De Sólidos, 2002.
A. Miravete
“New Materials and New Technologies applied to Elevators”. Elevator World (USA), 2002.- ISBN: 1886536-45-7
A. del Moral, M. J. Azanza, A. C. Calvo, R. N. Pérez Bruzón
“Cooperative diamagnetism and Ca2+ liberation of plasma membrane molecules explains the
nd
neuron responses to applied static and extremely low frequences magnetic fields”. En Proc 2 Int
Workshop On Biological Effects Of Electromagnetic.- Pp. 298-308.
M. L. Sanjuán, A. Ansón, M. T. Martínez
“Caracterización por espectroscopía Raman de nanotubos de carbono susceptibles de ser
utilizados como electrodos en supercondensadores”. En Proc I Workshop Red Pilas De CombustCSIC, 2002.- Pp. 289-292
M. L. Sanjuán
“Espectroscopía Raman de Materiales Componentes en Pilas de Combustibles de Oxido Sólido”.
En Proc I Workshop Red Pilas De Combust-CSIC, 2002.- Pp. 125-129.
A. Avenoza, J. H. Busto, C. Cativiela, F. Corzana, J. M. Peregrina, D. Sucunza, M. M. Zurbano
“Preparation and synthetic applications of (S)-and (R)-N-BOC-N,O-isopropylidene-αmethylserinals”. En Targets in Heterocyclic Systems. Chemistry and Properties, vol. VI.- Cambridge
(Reino Unido): Royal Society of Chemistry, 2003.- Pp. 232-244
M. A. Ciriano, L. A. Oro
“Pyridopyridines”. En Comprehensive Coordination Chemistry II, From Biology to Nanotechnology, vol.
I.- Nueva York, Elservier Pergamon, (2003).- Pp.55-61.
F. J. Fernández
“Simulation of quantum tunneling in an open system”. En Modeling of complex systems.- Nueva York,
Seventh Granada Lecture, (2003).- Pp. 242-250
M. C. Gimeno, A. Laguna
“Silver and gold”. En Comprehensive Coordination Chemistry II, vol. VI.- Nueva York, Elsevier
Pergamon, (2003).- Pp.83-92
J. J. Mazo
“Discrete breather in 2D Josephson junction arrays”. En Procedings of the 3rd Conference Localisation
and Energy Transfer in Nonlinear Systems.- World Scientific, (2003).- Pp. 320-322
195
J. J. Mazo, F. Falo, T. P. Orlando
rd
“Fluxon ratchet potentials”. En Proceedings of the 3 Conference Localisation and Energy Transfer in
Nonlinear Systems.- World Scientifc, (2003).- Pp 323-324
A. Miravete
“New materials and new technologies applied to elevators”. Estados Unidos, Elevator World, (2003)
L. A. Oro
“Hydrogenation by homogeneous catalysts”. En Encyclopedia of Catalysis, vol. IV.- John Wiley &
Sons, (2003).- Pp 55-107
L. A. Oro, E. Sola, J. Navarro
“Recent
developments
on
hydride
iridium
trisopropyphosphine
complexes,
[IrH2(NCCH3)3(PiPr3}]BF4 as hydrogenation catalyst”. En Perspectives in Organometallic Chemistry.RSC, (2003).- Pp 297-305.
196
3.3.- Tesis Doctorales
Ph.D. Theses
Título: Cryogenic Current Comparators with Optimum SQUID
Autor: Elena Bartolomé
Director: H. Rogalla, J. Flokstra, Conrado Rillo Millán
Calificación: Sobresaliente “cum laude”.
Título: Reactividad de ligandos coordinados: a) nitronas; b) tiolatos polifuncionales
Autor: Ana Moreno Ruíz
Director: Mariano Laguna Castrillo, Elena Cerrada Lamuela
Calificación: Sobresaliente “cum laude”.
Título: Catálisis heterogénea en la síntesis de precursores de (R)-2-(4-hidroxifenil)glicina
Autor: Beatríz Lázaro Peiró
Director: José Antonio Mayoral Murillo, José María Fraile Dolado
Calificación: Sobresaliente “cum laude”.
Título: Síntesis de nuevos edulcorantes tipo aspartame que incorporan fenilalaninas
restringidas
Autor: Miriam Alías Niño
Director: Carlos Cativiela Marín
Calificación: Sobresaliente “cum laude”.
Título: Estudio de reacciones de activación y acoplamiento en complejos con la unidad
ciclopentadienil-osmio
Autor: Miguel Baya García
Director: Miguel Ángel Esteruelas Rodrigo
Calificación: Sobresaliente “cum laude”.
Título: Complejos de oro y plata con ligandos que contienen selenio como átomo dador
Autor: Silvia Canales Cañas
Director: Antonio Laguna Castrillo
Calificación: Sobresaliente “cum laude”.
Título: Estudio de citocromos en configuración de bajo espín mediante espectroscopías EPR
ESEEM.
Autor: Inés García Rubio
Director: Pablo Javier Alonso Gascón, Jesús Ignacio Martínez Martínez
Calificación: Sobresaliente “cum laude”.
Título: Correlación entre parámetros de procesado, microestructura y propiedades físicas en
superconductores texturados de Bi2Sr2CaCu2O8+δ.
Autor: Eva Natividad Blanco
Director: Luis Alberto Angurel Lambán, Miguel Castro Corella
Calificación: Sobresaliente “cum laude”.
Título: Análisis y modelización del comportamiento a partir de preformas textiles
tridimensionales tipo "3D Braiding"
Autor: José Manuel Bielsa Gimeno
Director: Antonio Miravete de Marco
Calificación: Sobresaliente “cum laude”.
Título: Formación y reacciones de nuevos complejos hidruro de osmio
Autor: María Ángeles Tajada Serrano
Director: Miguel Ángel Esteruelas Rodrigo, Montserrat Oliván Escó
Calificación: Sobresaliente “cum laude”.
197
Título: Síntesis asimétrica de pirrolidinas altamente funcionalizadas. Aplicaciones a la síntesis
de aza nucleósidos
Autor: Julia Revuelta Crespo
Director: Pedro Merino Filella
Calificación: Sobresaliente “cum laude”.
Título: Estudio de reacciones de activación C-H/. Funcionalización sobre complejos lábiles de
iridio
Autor: Janeth Navarro Fuenmayor
Director: Eduardo Sola Larraya, Luis A. Oro Giral
Calificación: Sobresaliente “cum laude”.
Título: Nuevos complejos mono- y dinucleares de iridio: Actividad catalítica y reacciones de
activación
Autor: Francisco Torres Blasco
Director: Eduardo Sola Larraya, Ana Isabel Elduque Palomo
Calificación: Sobresaliente “cum laude”.
198
3.4.- Conferencias Invitadas
Invited Lectures
2002
Bistability and transitions in molecular
magnetic
materials
studied
by
calorimetry
R. Burriel
8th European Symposium on Thermal Analysis
and Calorimetry, Barcelona (España), agosto
2002
Nitrone Chemistry: Application to the
Synthesis
of
Highly
Functionalized
Pyrrolidines.
P. Merino
4th Italian-Spanish Symposium on Organic
Chemistry. Perugia (Italia), septiembre 2002
Reactivity and bonding features of rhodium
imido complexes
M. A. Ciriano, C. Tejel, L. A. Oro
35th International Conference on Coordination
Chemistry, Heildelberg (Alemania), julio 2002.
Síntesis
Estereoselectiva
de
Nuevos
Análogos de Nucleósidos.
P. Merino
XIX Reunión Bienal de Química Orgánica.
Carmona (Sevilla), junio 2002
Disconmensuration theory and ratchet
transport of modulated phases
L. M. Floría, F. Falo, P. J. Martínez, J. J. Mazo
Localization and energy transfer in nonlinear
systems, San Lorenzo de El Escorial (España),
junio 2002
Magnetic polymer nanocomposites of iron
oxides: a simple way to control particle size
dand composition
A. Millán, F. Palacio, I. Gilbert, A. Falqui, E.
Snoeck, V. Serin
3rd EPSRC Nanomagnetism Network Meeting.
Edimburgo (Reino Unido), mayo 2002
Synthesis and properties of polynuclear
gold-tallium complexes
A. Laguna, E. J. Fernández, J. M. López de
Luzuriaga, M. Monge, M. E. Olmos, J. Pérez
SFC Eurochem, Toulouse (Francia), julio 2002
Efectos cuánticos en nanoimanes
F. Luis, F. Mettes, G. Aromi, J. Bartolomé, L. J.
de Jongh
Reunión del grupo especializado de Física del
Estado Sólido (GEFES) de la Real Sociedad
Española de Física, Calella (España), 2002
Strategies for the immobilization of chiral
catalysts containing bis(oxazoline) ligands
J. A. Mayoral
IV Conference on Green Chemistry. Barcelona
(España), 2002
Discrete breathers in 2D Josephson-junction
arrays
J. J. Mazo
Localization and energy transfer in nonlinear
systems, San Lorenzo de El Escorial (España),
junio 2002
Análogos de nucleósidos con espaciadores
heterocíclicos:
Diseño
y
sintesis
estereoselectiva.
P. Merino
VI Semana Científica “Antonio González”. La
Química en el Siglo XXI. Universidad de La
Laguna (España), octubre 2002.
Sistemas estructurales con materiales de
nanotubos de carbono de altas propiedades
mecánicas
A. Miravete
VIII Congreso Nacional de Propiedades
Mecáncias de Sólidos. Gandía (España), junio
2002
Recent developments on hydrido iridium
triisopropylphosphine complexes
L. A. Oro, E. Sola, J. Navarro, V. Jiménez, F.
Torres
th
XX International Conference on Organometallic
Chemistry. Corfú (Grecia), 2002
Concluding Remarks
F. Palacio
VIIIth International Conference on Moleculebased Magnets, ICMM'02, Valencia (España)
octubre 2002
Grazing incidence diffraction anomalous fine
structure of InAs/InP self-asembled quantum
wires
M. G. Proietti, H. Renevier, S. Grenier, M. L.
González, J. M. García, A. Letoublon
NSLS’s Users Workshop, Brookhaven, Upton
N.Y. (USA), 2002
199
2003
Síntesis, characterisation and liquid cristal
properties of PAMAM and DAB Codendrimers.
J. Barberá, M. Marcos, J. M. Rueff, J. L.
Serrano, B. Donnio, D. Guillon
DENSOM-Euroconference Dendrimer Soft SelfAssembly Systems, York (Gran Bretaña),
septiembre 2003
Supermolecular liquid cristal dendrimer:
Liquid cristal organizations versus starburst
structures.
J. Barberá, M. Marcos, R. Martín, J. M. Rueff, J.
L. Serrano
VI Workshop Iberoamericano de fluidos
complejos y sus aplicaciones. Lisboa (Portugal),
septiembre 2003
Cadenas y ciclos metálicos en compuestos
de rodio e iridio
M. A. Ciriano, C. Tejel, L. A. Oro
XXIX Reunión Bienal de la Real Sociedad
Española de Química. Madrid (España), julio
2003
Fabricación de capas de eutéctico Al2O3-ZrO2
sobre sustrato de Al2O3 y su transformación
microestructural asistida por láser.
I. de Francisco, A. J. Sánchez-Herencia, R.
Moreno, J. I. Peña, R. I. Merino, A. Larrea, G. F.
de la Fuente, V. M. Orera
XLIII Congreso de la Sociedad Española de
Cerámica y Vidrio. Manises (España),
noviembre (2003)
Transport of fluxons in Josephson junction
arrays
F. Falo, J. J. Mazo, P. J. Martínez, K. Segall, T.
P. Orlando
Workshop, classical and quantum barrier
transport. Dresde (Alemania), mayo 2003
Localization and mobility in non-linear
shrodinger lattices
L. M. Floría, J. Gómez Gardeñes
Workshop, intrinsic localised modes and discrete
breathers in nonlinear lattices. Erice (Italia), julio
2003
Mechanistic Studies in Enantioselective
Catalysis. A Rational Way for Designing
Better Catalysts
J. I. García
7th Latin American Conference on Physical
Organic Chemistry. Florianópolis (Brasil)
Self-organised nano structures
D. Guillon, B. Donnio, L. Gehringer, J. L.
Serrano, M. Marcos, R. Deschenaux.
DENSOM-Euroconference Dendrimer Soft SelfAssembly Systems. York (Gran Bretaña),
septiembre 2003
Magnetism fo nanometric 3-d particles in
carbon cages: possible relevance for medical
applications
M. R. Ibarra
Spring Meeting European Material Research
Society “New Trends in Nanoscience”.
Estrasburgo (Francia), junio 2003
The new alchemist: New applications of gold
A. Laguna
Not strictly inorganic chemistry. Prullans
(Gerona, España), marzo 2003
Complexes
F. J. Lahoz
st
21 European Crystallographic Meeting. Durban
(South Africa), agosto 2003
Structural knowledge: a key step in the
progress of Homogeneous catalysis
F. J. Lahoz
Workshop on “Opportunities for Synchrotron and
Neutron Diffraction in Nanosciences. Bath (Reino
Unido), abril 2003
The approach to thermal equilibrium of
nanomagnets
F. Luis, F. Bartolomé, J. Bartolomé, V. Cross, M.
Evangelisti, J. L. García Palacios, L. M. García,
V. González, H. Jaffrès, L. J. de Jongh, F. L.
Mettes, F. Petroff, J. Stankiewicz.
Physics of nanoscale magnets. Kyoto (Japón),
2003
Approach of single-molecule magnets to
thermal equilibrium
F. Luis, F. L. Mettes, M. Evangelisti, A. Morello,
L. J. de Jongh
European Materials Research Symposium.
Estrasburgo (Francia), 2003
Comportamiento magnético de proteínas de
seres vivos
F. Luis
1ª Reunión sobre aplicaciones de la nanociencia
en medicina. Zaragoza (España), 2003
Liquid cristal Dendrimers based on PAMAN
and DAB: Influence of the central core,
mesogenic units and terminal chains on the
supramolecular organisation.
M. Marcos, J. L. Serrano
DENSOM-Euroconference Dendrimer Soft SelfAssembly Systems. York
(Gran Bretaña),
septiembre 2003
Rotobreathers
in
two-dimensional
Josephson arrays
J. J. Mazo, D. Zueco
Workshop, intrinsic localised modes and discrete
breathers in nonlinear lattices. Erice (Italia), julio
2003
200
Ceramic composites produced by laser
assited directional solidification with eutectic
and near eutectic composition.
R. I. Merino, J. I. Peña, I. de Francisco, P. B.
Oliete, A. Larrea, V. M. Orera
105th Annual Meeting and Exposition of The
American Ceramic Society. Nashville (Tenesse,
USA), abril (2003).
Small-angle neutron scattering in Ga-doped
manganites
J. M. de Teresa, P. A. Algarabel, M. R. Ibarra, L.
Morellón, J. Blasco, C. Ritter, J. I. Espeso, J. C.
Gómez-Sal
Workshop on “Intrincsic inhomogeneities in
strongly
correlated
electron
systemes”,
Santander (España), febrero 2003
Quantum
phenomena
in
magnetic
nanoclusters
F. L. Mettes, F. Luis, M. Evangelisti, A. Morello,
L. J. de Jongh
Quantum Phenomena on the Large Scale. Banff
(Canadá), 2003
Structrural,
magnetic
and
transport
properties of half-metallic double perovskites
J. M. de Teresa, D. Serrate, J. Blasco, L.
Morellón, M. R. Ibarra, C. Ritter
Workshop
on
Self
Organized
Strongly
Correlated Electron Systems. Santorini (Grecia),
agosto 2003
The naturally nanolayered R5(SixGel1-x)4
materials
L. Morellón, P. A. Algarabel, C. Magén, Z.
Arnold, C. Ritter, M. R. Ibarra
th
International Conference on f-elements
5
(ICFE)
Role of the interface in oxide-based
magnetoresistive systems
J. M de Teresa, D. Serrate, P. A. Algarabel, L.
Morellón, M. R. Ibarra
European Materials Research Symposium.
Estrasburgo (Francia), 2003
Functional Properties of Melt Growth
Ceramic Eutectics
V. M. Orera
Directionally Solidified Eutectic Ceramics
Workshop. París (Francia), 2003
Functional properties of melt-grown eutectic
composites
V. M. Orera, J. I. Peña, R. I. Merino, A. Larrea,
G. F. de La Fuente
Directionally Solidified Eutectic Workshop. París
(Francia), mayo 2003
Processing, microstructure and mechanical
behavior of directionally solidified eutectic
ceramic oxides.
V. M. Orera, J. I. Peña, R. I. Merino, A. Larrea,
J. LLorca, J. Y. Pastor, P. Poza, J. Martínez, A.
Ramírez, M. López, J. Quispe
th
Annual Conference on Composites,
27
Advanced Ceramics, Materials, and Structures.
Cocoa Beach (Florida, USA), enero 2003
Magnetic behaviour of S-based free radicals:
On the way to high Tc organic magnets
F. Palacio
Clusters and particles. Okazaki (Japón), febrero
2003
Metal-free high Tc organic magnets
F. Palacio
DFG Priority Programme on molecular
magnetism. Blaubach (Alemania), mayo 2003
Magnetismo y transporte polarizado en espín
en la nanoescala
J. M. de Teresa
III Reunión de la Red Nacional de Nanociencia.
Oviedo (España), noviembre 2003
201
4.- Cooperación Científica
Scientific Cooperation
203
4.1.- Unidades Asociadas al ICMA
ICMA Partner Laboratories
Grupo de Síntesis Química de La Rioja (Universidad de la Rioja)
Chemical Synthesis Group of La Rioja (University of La Rioja)
● Personal científico permanente / Scientific staff
−
Lalinde Peña, Elena
Prof. Titular, Responsable de la Unidad Asociada
−
−
−
−
−
−
−
−
−
Campos García, Pedro José
Avenoza Aznar, Alberto
Berenguer Marín, Jesús Rubén
Fernández Garbayo, Eduardo J.
López de Luzuriaga, José María
Moreno García, Teresa
Olmos Pérez, Elena
Peregrina García, Jesús M.
Zurbano Asensio, Mª Mar
Catedrático
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Científico responsable en el ICMA / Local coordinator at ICMA
− Prof. Juan Forniés Gracia
Grupo de Materiales Orgánicos Avanzados (Universidad Jaime I)
Advanced Organic Materials Group (University Jaime I)
● Personal científico permanente / Scientific staff
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Luis Lafuente, Santiago
Catedrático, Responsable de la Unidad Asociada
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−
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Altava Benito, Belén
Burguete Azcárate, Isabel
Escuder Gil, Beatriz
Miravet Celades, Juan F.
Prof. Titular
Prof. Titular
Prof. Titular
Prof. Titular
Científico responsable en el ICMA / Local coordinator at ICMA
− Prof. José Antonio Mayoral Murillo
205
4.2.- Convenios con Organismos Extranjeros
Collaborative Agreements with Foreign
Institutions
Laboratorio Europeo Asociado LEA - MANES
Associated European Laboratory LEA - MANES
El Laboratorio Europeo Asociado (LEA) para
el estudio de materiales por difracción de
neutrones y radiación de sincrotrón (MANES) se
constituyó por Convenio entre el Instituto de
Ciencia de Materiales de Aragón y el
Laboratorio de Cristolografía del CNRS de
Grenoble el 25 de junio de 1993 con las firmas
del Presidente del CSIC, del Rector de la
Universidad de Zaragoza, del Director General
del CNRS y del Presidente de la Universidad J.
Fourier de Grenoble.
Sus temas de investigación se inscriben en
dos líneas: El estudio de las propiedades
estructurales, termodinámicas, magnéticas y
electrónicas de materiales magnéticos y
conductores; y el desarrollo de técnicas de
difracción, de difusión y de espectroscopia
adaptadas a los materiales producidos por los
laboratorios cooperantes y su operación en las
grandes instalaciones ILL y ESRF.
La formación en investigación e intercambios
de personal son también objetivos esenciales de
esta cooperación.
Temas de trabajo:
1. Síntesis
y
propiedades
estructurales,
termodinámicas, magnéticas y electrónicas de
materiales magnéticos.
- Síntesis de nuevos compuestos intermetálicos
de tierra rara y metal de transición.
- Propiedades de materiales magnéticos duros.
- Modelización de anomalías de reorientación
de spin.
- Anomalías en la susceptibilidad magnética ac.
- Efecto Hall en monocristales de intermetálicos
de tierra rara y metal de transición.
2. Utilización de técnicas de dispersión de
neutrones y radiación de sincrotrón.
- Magnetismo y radiación de sincrotrón.
- Espectroscopía de absorción de rayos-x
(XAS, XANES, EXAFS).
- Dicroísmo magnético circular en la absorción
de rayos-x (XMCD).
- Dispersión magnética resonante en la
absorción de rayos-x (XRMS).
- Dispersión inelástica resonante de rayos-x
(RIXS).
- Desarrollo de técnicas de difracción.
The Associated European Laboratory (LEA)
for the study of materials with neutron diffraction
and synchrotron radiation (MANES) was
established by an Agreement between the
Aragón Materials Science Institute and the
CNRS Laboratory of Crystallography in
Grenoble on June 25, 1993. The Agreement was
signed by the President of the CSIC, the Rector
of the University of Zaragoza, the General
Director of the CNRS and the President of the
University Joseph Fourier of Grenoble.
The research topics of the Laboratory are
grouped into two areas -- (1) The study of
structural, thermodynamic, magnetic and
electronic properties of materials; and (2) the
development of diffraction, scattering and
spectroscopic techniques adapted to the
materials produced in the collaborating
laboratories and to operations at the facilities ILL
and ESRF.
Reasearch training and scientific exchange
are also essential goals of this agreement.
Research topics:
1. Synthesis and structural, thermodynamic,
magnetic and electronic properties of magnetic
materials.
- Synthesis of new intermetallic compounds of
rare earths and transition metals.
- Properties of hard magnetic materials.
- Modelling of spin reorientation materials.
- Ac magnetic susceptibility anomalies.
- Hall effect in single crystals of rare earth and
transition metal intermetallics.
2. Use of neutron scattering techniques and
synchrotron radiation.
- Magnetism and synchrotron radiation.
- X-ray absorption spectroscopy (XAS, XANES,
EXAFS).
- X-ray magnetic circular dichroism (XMCD).
- X-ray resonant magnetic scattering (XRMS).
- Resonant inelastic X-ray scattering (RIXS).
- Development of diffraction techniques.
Director: Prof. Ramón Burriel
Director: Prof. Ramón Burriel
206
Instrumento CRG: Difractómetro de neutrones D1B
CRG: The D1B beamline neutron diffractometer
El CSIC mantiene la explotación del CRG
(Collaborating Research Group) D1B en el ILL
(Instituto von Laue Langevin, Grenoble, Francia)
en colaboración con el CNRS. La coordinación
científica y administrativa la realiza el ICMA, que
ha tenido como científicos responsables
contratados en el lugar durante este período a
Javier Campo Ruiz y David Martín Marero.
The CSIC oversees the use of the CRG
(Collaborating Research Group) D1B beamline
at the ILL (Institute von Laue Langevin,
Grenoble, France) in collaboration with the
CNRS. ICMA is responsible for scientific and
administrative coordination and has had Javier
Campo Ruiz and David Martín Marero in place
as local coordinators.
El D1B es un difractómetro de polvo de dos
ejes para experimentos que precisan una
intensidad de flujo alta. En ángulos pequeños se
obtienen altas resoluciones espaciales con
anchuras (FWHM) de 0.2º para muestras con
diámetro de 8 mm.
D1B is a two-axis powder diffractometer
dedicated to diffraction experiments requiring a
high neutron flux. At small angles a high spatial
resolution can be achieved with a width (FWHM)
of 0.2º for samples with a diameter of 8 mm.
El D1B está equipado con un detector
posición compuesto por un sistema
multielectrodos con 400 celdas y un rango
80º que puede moverse para cubrir un sector
160º.
de
de
de
de
- Magnetismo: Determinación de estructuras
magnéticas, estudio de transiciones de
reorientación de spin.
-
Applications of D1B:
- Magnetism: Determination of magnetic
structures, study of spin reorientation transitions.
Aplicaciones en el D1B:
- Estudio de transiciones
termodifractometría.
D1B is equipped with a position sensitive
detector composed of a system of multielectrodes with 400 cells which span a range of
80º and can be moved to cover a sector of 160º.
de
fase
por
Estudios cinéticos con resolución temporal.
- Investigation of
thermodiffractometry.
phase
transitions
by
-
Time resolved kinetic studies.
-
Dynamical studies in solid state chemistry.
-
In situ neutron diffraction.
- Estudios dinámicos en química de estado
sólido.
- In situ chemistry, chemical intercalation, gassolid reactions.
-
-
Difracción de neutrones in situ.
Texture analysis.
- Reacciones químicas in situ, intercalación
química, reacciones gas-sólido.
-
Análisis de texturas.
207
4.3.- Estancias de Investigadores del ICMA en
Otros Centros (≥ 2 Semanas)
Scientific Visits to Other Institutions (≥ 2
Weeks)
2002
Bartolomé Usieto, F.
Spring (Japón) / 2 semanas
Bartolomé Usieto, F.
Lawrence Berkely National Laboratory (USA) / 2 semanas
Burriel Lahoz, R.
Tokyo Institute of Technology (Japón) / 2 semanas
Campo Ruíz, J.
Universidad de Sao Paulo. Instituto de Física (Brasil) / 9 semanas
Campo Ruíz, J.
Institut Laue Langevin, Grenoble (Francia) / 9 meses
Cuesta López, S.
Ècole Normale Supérieure de Lyon (Francia) CNRS, UMR, 5672 / 6 meses
Chaboy Nalda, J.
Laboratori Nazionale di Frascati del I.N.F.N., Roma (Italia) / 1 mes
Chaboy Nalda, J.
Spring, Hyogo (Japón) / 1 mes
Falvello, L. R.
Texas A&M University (USA) / 1 mes
Falvello, L. R.
Intense Pulsed Neutron Source, Argonne National Laboratory (USA) / 6 semanas
Floría Peralta, L. M.
Institute of Mathematics, University of Warwick (Reino Unido) / 1 mes
Floría Peralta, L. M.
Max-Planck-Institut für Physik Komplexer Systeme, Dresden (Alemania) / 6 semanas
Floría Peralta, L. M.
FORTH, Heraklion (Grecia) / 3 meses
García Palacios, J. L.
Universidad de Uppsala (Suecia) / 3 meses
García Vinuesa, L. M.
Lawrence Berkely National Laboratory (USA) / 2 semanas
Lasa Ventura, M.
Universidad de Oviedo (España) / 10 semanas
208
Luis Vitalla, F.
Institute Laue Langevin, Grenoble (Francia) / 3 semanas
Marquina García, C. I.
University of Warwick (Reino Unido) / 2 semanas
Mazo Torres, J. J.
Massachusetts Institute of Technology, Cambridge (USA) / 1 mes
Palacio Parada, F.
Universidad de Sao Paulo (Brasil) / 2 semanas
Palacio Parada, F.
Univesidad de Cambridge (Gran Bretaña) / 9 semanas
Proietti, M. G.
Laboratoire de Cristallographie (Grenoble, Francia) / 1 mes
Royo Gracia, S.
Parque Científico de Barcelona (España) / 2 meses
Serrano Ostáriz, J. L.
Univesidad de Bayreuth (Alemania) / 1 mes
Subías Peruga, G.
European Synchrotron Radiation Facility (ESRF), Grenoble (Francia) / 2 semanas
Teresa Nogueras, J. M. de
Laboratoire de Physique de la Matière Condensée. Toulouse (Francia) / 4 semanas
2003
Badorrey Miguel, R. A.
Universidad de Groningen (Holanda) / 5 meses
Campo Ruíz, J.
Universidad de Sâo Paulo (Brasil) / 3 semanas
Campo Ruíz, J.
Laboratoire Leon Brillouin, Saclay (Francia) / 4 semanas
Campo Ruíz, J.
Institut Laue Langevin, Grenoble (Francia) / 4 semanas
Chaboy Nalda, J.
Laboratori Nazionale di Frascati del I.N.F.N., Roma (Italia) / 1 mes
Chaboy Nalda, J.
Spring, Hyogo (Japón) / 1 mes
Falvello, L. R.
Intense Pulsed Neutron Source, Argonne National Laboratory (USA) / 1 mes
Palacio Parada, F.
Universidad de Tokyo (Japón) / 2 meses
Proietti, M. G.
Laboratoire DRFMC-SP2M, CEA, Grenoble (Francia) / 2 meses
209
Rodríguez Martínez, F. J.
University of Technology and Economics, Budapest (Hungría) / 1 mes
Serrano Ostáriz, J. L.
Universidad de Concepción (Chile) / 2 semanas
Subías Peruga, G.
European Synchrotron Radiation Facility (ESRF), Grenoble (Francia) / 4 semanas
210