1st year REPORT - TU Wien · 1st year REPORT of ALFA II Network: HIFIELD ... Para ser aceptado este informe debe estar firmado por el interlocutor (persona responsable de la ... Centro

2

1st year REPORT

of

ALFA II Network: HIFIELD

Project number II0147FI

“Measurement methods involving high magnetic

fields for advanced and novel materials”

Prof. Roland Grössinger, T.U.Vienna, Austria (coordinator) (TUV) Dr.Jose Matutes , Centro de Investigacions en Materiales Avanzados; Mexico (IM) Dr. JM Broto , LNCMP. Toulouse, France (LNCMP) Prof. Hywel Davies and Prof Mike Gibbs, Univ. Sheffield, U.K. (US) Prof. Joao Paulo Sinnecker, Univ. Rio de Janeiro, Brazil (UR) Prof. Ernesto Estevez-Rams, Univ. Havana, Cuba (UH) Prof. Vicente Sagredo + Prof. Gonzales, Univ de los Andes, Venezuela (UV) Prof Hector Bertorello, Univ Cordoba, Argentina (UC)

Web-page: http://www.ifp.tuwien.ac.at/forschung/alfa/

http://www.ifp.tuwien.ac.at/forschung/alfa/

3

αlfa – INFORME TÉCNICO

FINAL 1

Red : HIFIELD N° del contrato : II0147FI Proyecto : Measurement methods involving high manetic fields for advanced and novel materials Institución coordinadora : Techn. Univ. Vienna Fecha de firma: 1. December 2002 Duración prevista: 36 months (fecha de entrada en vigor del contrato) en el contrato

Tipo de Proyecto: Sub-program B Campo principal: Physics Objeto del proyecto: Training of young scientist and students in producing new materials,

characterising them and training in measurement methods in high magnetic fields. Periodo al que se refiere el informe final: de: ...01. /12... /02...

a: ...01 / .12... / 03....

Interlocutor: 2 Nombre completo: Roland Grössinger Cargo: Univ. Prof. Facultad/Departamento/servicio: Inst. f. Festkörperphysik; Techn. Uiv. Vienna Firma: R.G. Fecha: 15. Dec. 2003 Representante legal: ²

Nombre completo: Walter Steiner Cargo: Univ. Prof. Head of Institute Firma: W.St. Fecha: 7. Jan. 2004

1 Modelo a utilizar para pre-proyectos y proyectos 2 Para ser aceptado este informe debe estar firmado por el interlocutor (persona responsable de la

ejecución del proyecto) y por el Representante legal de la institución coordinadora (Persona que firmó el contrato)

4

RESULTADOS GLOBALES

En caso de un proyecto de mobilidad, incluir una lista de los becarios (Nombre, Universidad de origen, Universidad de acojida y periodo de Estancia°

Sintetizar las actividades realizadas

Main activities were students and/or professors exchange. The aim of the

students exchange was the learning of new experimental methods. In the

professors meetings courses for local students were given, additionally many

very valuable discussions with the local people were possible. Additionally two

“summer courses” (Chihuahua, Toulouse) for all participants were given. There

from each group tutorial introductions but also valuable scientific presentations

were given. This allowed an exchange of ideas on the technical as well as on

the scientific side.

Citar la metodología utilizada para la evaluación de las actividades

All presentations were discussed – here also the young members of the group

were included. At the end of each f these meeting a summary with a

presentation of the open problems were given – see also the report.

Describir los resultados logrados y su concordancia con los objetivos

previstos, no olvide incluir los productos mismos (publicaciones, actas de

reuniones, libros, CDrom etc. , asi como la dirrección del sitio web).

The first results were already published – see abstracts at the end of the

report. The presentations of each meeting can be seen at our alfa-web page:

Web-page: http://www.ifp.tuwien.ac.at/forschung/alfa/

http://www.ifp.tuwien.ac.at/forschung/alfa/

5

Describir los problemas encontrados

There sould be more local students icluded. The problems is that some f these

groups have only a small number of students. It was successfull to include the

Summer scool into local meetings such as that of the LAW3M in Chihuahua.

This way should be continued.

Main administrative problems occure due to difficulties with money transfers

into countries with political or ecconomical problems.

Sugerencias

6

List of scolarships

NAME Original Institute Host Institute from until

Ernesto Estevez

Rams

Univ. de la Habana Techn. Univ.

Vienna

1. March 15. March

H. Rakoto NLMF Toulouse University of

Los Andes,

Merida

Venezuela

9. June 14 June

Jose Hiram Espina Univ. de la Habana Techn. Univ.

Vienna

July December

Miguel Alexandre Novak and

Maria das Graças

Fialho Vaz

Instituto de Física da Universidade Federal do Rio de Janeiro

Techn. Univ.

Vienna

2. August 6. August

Ricardo Martinez

Gracia

Merida, Venezuela NLPMF,

Toulouse,

France

17. October 1. December

7

RESULTADOS GLOBALES


Ernesto Estevez Rams, Universidad de la Habana, Technische Universitat

Wien, 15 days (March 2003)


Ernesto Estevez came as visiting professor to Vienna where he discussed about

magnetic materials characterization using X-ray diffraction and electron

microscopy. The system Sm(Co,Cu)5 which shows a giant magnetic viscosity

was discussed as an ongoing joint research Project between the Vienna and

Havana group. Further work on a slightly modified system SmY(Co,Cu)5 was

discussed and the first characterization of the systems was made.

The system FeSiNb with different Nb content was also discussed and a joint research

effort was started, it was agreed to involve a student from Havana, MSc.

Arbelio Penton Madrigal the characterization of this simples as part of his PhD

studies. Samples were prepared and exchanged.

Calibration of pulse magnetic field using planar coils is an open problem. The subject

was discussed by Ernesto Estevez Rams exploring the idea of using directly

the induction law for this special geometry in order to perform the calibration.

The visit to Vienna for 6 month of PhD student MSc. Jose Hiram Espina was

coordinated. It was agreed that Espina should go to Vienna to learn about

pulse magnetic field. A working plan was decided. Espina will be involved in

the development of planar coils for pulse magnetic field system.

8

Nanocrystalline hexaferrite sample preparation was discussed. Professor Ernesto

Estevez Rams has experience in preparing such samples lowering the

synthesis temperature by modification of the original sol-gel process. One

student from Vienna is studying such systems and discussion was held on

which could be the best path to obtain the nanocrystalline samples.

9

Rakoto (Toulouse)

Theoretical and Practical Workshop Inform Merida – Venezuela

June 9th – 14th, 2003 Centro de Estudios de Semiconductores

Physics Department, Science Faculty University of Los Andes, La Hechicera

The Theoretical part of the Workshop took place every morning from 09:00 am to 12:30 pm, from Monday to Friday. The courses were given by B. Raquet, J.M. Broto, and J. González. All the subjects in the program were developed (Program enclosed). In the afternoon took place the practical part ( 3-7pm) at the High Field Magnetic Pulsed laboratory of the Centro de Estudios de Semiconductores of Merida , the students were divided in groups of 6 and they made 3 lab practices with the participation of H. Rakoto, P. Bocaranda, Ch. Power, B. Raquet, J.M. Broto and J. González. The practices were:

- Colossal magnetoresistence in the thin film La2/3Ca1/3Mn03 (4–240 K, 0–20 T); - Magnetization function of B to study the order transition Sm0.475Sr0.525Mn03 (4 K,0–

20 T) - Handling of diamonds pressure cell and pressure scale: ruby luminescence

10

Report Espina (July- Dec. 2003- 6 months; Vienna) Investigation of local probe measuring systems which can be used for pulsed fields Activities: - Presentation of a poster in the RHMF2003, Toulouse, France. - Talk entitled "New Sensors for measuring M and H in High Pulsed Fields" in the Second School of the Alfa, Toulouse, France. - Paper acepted for the proceeding of the RHMF 2003 that will be published in Physica B. - Research carried out at the TU-Vienna under the supervision of Prof. Groessinger * Measurements of local eddy currents in Cu and Al discs * Measurements to perform the calibration of the magnetization in physical units, using surface pick-up coils * Design and cosntruction of a new pick-up coil holder to perform precise measurements * Calibration of standard pick-up coils measuring systems to give comparisons with the measurements of the surface pick-up coil. - Paper published in Journal of Alloys and Compounds 2004 This activities helped to finish the experimental studies at the TU-Vienna in order to fulfill all the requirements for the presentation of a dissertation at the University of Havana to get the degree of Doctor in Thecnical Science.

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12

Novak (July 2003 Vienna)

Mission report

ALFA Project Miguel Alexandre Novak and Maria das Graças Fialho Vaz Instituto de Física da Universidade Federal do Rio de Janeiro Working Mission at TUWIEN from August 2 until august 6th 2003. We both were in Florence, Italy, after the ALFA Meeting and RHMF workshop in Toulouse and the ICM2003 conference in Rome. There we worked in the group of Prof. Dante Gatteschi, with which we have a long time colaboration. It was agreed that we would make a short working visit to Viena befor returning to Brazil. We went by a rented car, as it would be cheaper than 2 flights. In Viena, where we were for the first time, we started to use the pulsed field magnetometer, in order to get aquainted with this technique which we never used before. We learned well how to use the system, and made some exploratory measurements on two molecular magnet samples, a Co Semiquinone, and Mn semiquinone based material which undergoes a spin transition induced by pressure and temperature. The aim was to check if the spin transition in this compounds could be induced by a field. Preliminary measurements showed that indeed the spin changes from room temperature to low temperature. Unfortunately the temperature control of the systems needs some improvements, and the transition would be seen in a narrow temperature and field window. Besides that the measurements should also go to higher fields. These measurements allowed us to plan future experiemnts and to stimulate the synthesis of other similar molecular compounds. This synthesis is being now made at the UFRJ By Dr. Maria Vaz and the student Margot Kalisz. Preliminary measurements in a quasi static field up to 14 T will also be made at the low temperature lab of UFRJ by Drs. Sinnekcer and Novak. The visit to Tuwien served also to make new contacts with other researchers interested in the new exciting field of molecular magnetism, interested in transport , mossbauer spectroscopy and specific heat measurements.

13

RESULTADOS GLOBALES


Name: Ricardo Martínez García From: IMRE-Universidad de la Habana, Cuba Stay: National Laboratory of Pulsed Magnetic Fields, University “Paul Sabatier”, Toulouse, France. 1ers stay of 6 months (Octubre 2003 a Abril 2004).


• Presentation of the proposed work to the interested parts in the National Laboratory of

Pulsed Magnetic Fields. This activity is carried out in order to plan the investigation and experiments to do in the future.

• Bibliographical review using the facilities of the National Laboratory of Pulsed Magnetic Fields and of the University “Paul Sabatier” Toulouse III.

• Meeting with the Pr. Azzedine Bousseksou of the National Laboratory of Chemistry of Coordination, specialist in the topic "coordination molecular materials".

• Highly specialized bibliographical review using the facilities given by the Pr. Azzedine Bousseksou of the National Laboratory of Chemistry of Coordination.

• Design of the experiments to carry out using the facilities of the National Laboratory of Pulsed Magnetic Fields and of the National Laboratory of Chemistry of Coordination.

• Experimental measurements in order to do samples characterization.

Citar la metodología utilizada para la evaluación de las actividades

Describir los resultados logrados y su concordancia con los objetivos

previstos, no olvide incluir los productos mismos (publicaciones, actas de

reuniones, libros, CDrom etc. , asi como la dirrección del sitio web).

14

• Highly specialized bibliographical review using the facilities of the National Laboratory of

Pulsed Magnetic Fields and of the University “Paul Sabatier” and the facilities given by the Pr. Azzedine Bousseksou of the National Laboratory of Chemistry of Coordination.


• Experimental measurements in order to do samples characterization.

Describir los problemas encontrados

Sugerencias

Ricardo Martinez (Cuba - Toulouse) Work Report (October 17, 2003 at December 1, 2003) Project : "Tuning the magnetic properties in Prussian Blue Analogs" Author : Ricardo Martinez Garcia National Laboratory of Pulsed Magnetic Fields, Toulouse, France Alpha Project Introduction Since the discovery of the lode-stone (FeO-Fe2O3), many different magnetic materials have been developed, ceramics, intermetallics or molecular magnetic materials. In the last years the control of the magnetic properties of molecular materials through external stimulation, like light or heat, has been demonstrated [1, 4]. The control of magnetic properties by light has been a subject of increasing attention, particularly from the finding of spin switching effect in Nickel Nitroprusside [2, 3] and the photo-induced magnetization in Cobalt Iron cyanide [4]. The photo-induced effect in the Cobalt Iron cyanide system happens when this material is irradiated with visible light at 19 K or below and a magnetic state is induced [4]. That photo-induced magnetization is attributed to a charge transfer in FeII(t2g

6, eg0; S=0)-C≡N-CoIII(t2g

6, eg

0; S=0) to form FeIII(t2g5, eg

0; S=1/2)-C≡N-Co2+(t2g5, eg

2; S=3/2). Aims 1. To study the effect of the Co(2+):Co(3+) ratio in the mixed valence Fe-CN-Co system

(MVS) on the properties of the photo-induced magnetic state. 2. To obtain experimental confirmation about the probable role of the crystallization water on

the photo-induced effect. 3. To study the effect of the different adsorbed species (e.g. NH3, MetOH, EtOH, H2O) in the

MVS system on the properties of the photo-induced magnetic state. 4. To extend the study of the magnetic photo-induced effect to the system Fe-CN-Me, where

Me is Mn, Fe, Ni, Cu, and Zn.

15

Expected results: a) An exhaustive study on the role of the adsorption on the photo-induced magnetic

properties of the studied materials. b) An understanding on the effect of crystallization water and other exchangeable species on

the electronic structure, and in consequence in the magnetic properties, in the families of the studied materials.

c) Publication of at least two join papers in Condensed Matter Physics Journals. References 1) O. Sato, T. Iyoda, A. Fujishima and K. Hashimoto, Science, 271 (1996), 49 2) Z. Gu, O. Sato, T. Iyoda, A. Fujishima and K. Hashimoto, J. Phys. Chem., 100 (1996),

18289 3) Z. Gu, O. Sato, T. Iyoda, A. Fujishima and K. Hashimoto, Chem. Mater., 9 (1997), 1093 4) O. Sato, T. Iyoda, A. Fujishima and K. Hashimoto, Science, 272 (1996), 704 In order to execute this project we did the following actions: • Presentation, by the author, of the proposed work to the interested parts in the National

Laboratory of Pulsed Magnetic Fields. This activity is carried out in order to plan the investigation and experiments to do in the future.

• Bibliographical review using the facilities of the National Laboratory of Pulsed Magnetic Fields and of the Universidad Paul Sabatier Toulouse III.

• Meeting with the Pr. Azzedine Bousseksou of the National Laboratory of Chemistry of Coordination, specialist in the topic "coordination molecular materials".

• Highly specialized bibliographical review using the facilities given by the Pr. Azzedine Bousseksou of the National Laboratory of Chemistry of Coordination.


The previous actions will give place to the realization, in the immediate future, of: • Low temperatures measurements in SQUID, under light, of the samples of the system Fe-

CN-Co. • Low temperatures measurements in Mossbauer of the samples of the system Fe-CN-Co. • Measurements in pulsed magnetic fields of the samples of the system Fe-CN-Co. Toulouse, December 3, 2003

16

Members of the 1st ALFA meeting in Chihuahua (Mexico)

17

1st ALFA MEETING

“Measurement methods involving high magnetic fields for advanced and

novel materials”

Together with LAW3M

in

CHIHUAHUA (MEXICO)

18

Alfa Project on High Magnetic Fields

SUNDAY, APRIL 6th 9:00-10:00

10:00-10:30 Hywel Davies Univ. Sheffield, UK

10:30-11:10 Adv

ance

d M

ater

ials

Vicente Sagredo ULA, Venezuela

11:10-11:30 Coffee Break

11:30-12:00 Hector Bertorello Univ. Córdoba, Argentina

12:00-12:30

12:30-13:00

13:00-13:30

Lunch

13:30-14:00 Ernesto Estevez Rams Univ. Havana, Cuba

14:00-14:30 Cha

ract

eri-

zatio

n of

M

ater

ials

Joao Paulo Sinnecker U. Rio de Janeiro, Brazil

14:30-15:00 J. M. Broto LNCMP, Toulouse, France

15:00-15:30 Roland Grössinger T. U. Vienna, Austria

15:30-16:00 Hig

h M

agne

tic F

ield

s

José Matutes CIMAV, Mexico


16:30-17:00

17:00-18:00

Discussion about the further organization of the project

18:00-19:00

19:00-20:00 Free

20:00 Dinner

SATURDAY, APRIL 5th

9:00-10:00 Registration

10:00-10:30 Opening Ceremony

10:30-11:00 R. Grössinger T. U. Vienna

Presentation of general idea and targets of the project


11:30-12:00

12:00-12:30

R.Grössinger T. U. Vienna, Austria

Organization and financial aspects of the project

12:30-13:00

13:00-13:30

13:30-14:00

Lunch

14:00-14:20 José Matutes CIMAV, Mexico

14:20:14:40 Vicente Sagredo ULA, Venezuela

14:40-15:00 Joao Paulo Sinnecker U. Rio de Janeiro, Brazil

15:00-15:20 Ernesto Estevez Rams Univ. Havana, Cuba

15:20-15:40

Labo

rato

ry F

acili

ties

Hector Bertorello Univ. Córdoba, Argentina


16:00-16:20 J. M. Broto LNCMP, Toulouse, France

16:20-16:40 Hywel Davies, Mike Gibbs Univ. Sheffield, UK

16:40-17:00

Labo

rato

ry

Faci

litie

s

Roland Grössinger T. U. Vienna, Austria

17:00-18:00

18:00-19:00 Free

19:00 Dinner

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VI Latin American Workshop on Magnetism, Magnetic Materials and their Applications

April 7th-11th 2003 Chihuahua Mexico

Sponsored by:

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Workshop Summary The “Centro de Investigación en Materiales Avanzados” (CIMAV) organized the Sixth Latin American Workshop on Magnetism, Magnetic Materials and their Applications during April 7-11, 2003 in Chihuahua Mexico. The main objective of the Workshop was to support scientific exchanges among researchers and institutions interested on recent developments in all branches of fundamental and applied magnetism. The Workshop was held under the auspices of the local government, and sponsored by the International Union of Crystallography (IUCr), The Abdus Salam International Centre for Theoretical Physics (ICTP), International Union of Pure and Applied Physics (IUPAP), Centro Latinoamericano de Física (CLAF) and The National High Magnetic Field Laboratory (NHMFL). The event was specifically tailored for researchers and students belonging to universities and research organizations to learn about the latest developments in the area of magnetism, magnetic materials and new applications. 60 young scientist from Argentina, Czech Republic, Belgium, United States, Brazil, Cuba, El Salvador, Venezuela, Chile, Austria, Poland, France and Mexico participated in the Workshop. Distinguished scientists from France, Austria, Ireland, Spain, United States, Brazil, United Kingdom, Argentina and Mexico delivered 23 lectures focusing on the physical concepts and the phenomena in magnetism, covering a wide spectrum ranging from nano-magnetic materials, magnetic recording, synthesis of new soft and hard magnetic materials, magnetic composites, thin films, etc. The inaugural addresses were given by Dr. Sebastián Díaz De La Torre (CIMAV) and Dr. Javier Sanchez Reaza (Secretary of Industrial Development), while Dr. José Matutes Aquino (CIMAV), Mr. Hector Jaime Muñoz (Secretary of Education and Culture), Mrs. Miriam Sandoval (local government) and Dr. Sanchez Granillo (University of Chihuahua) were part of the presidium. The Workshop featured a visit to CIMAV´s laboratories, two technical sessions, three poster sessions, one forum on International Collaboration and one Symposium on International User Facilities in Support of Magnetic Related Research. On behalf of the organizers, Dr. José Matutes made the closing remarks and extended best wishes to the participants.

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Invited Talks The duration of each lecture was either 30 or 45 minutes, for lecture and tutorial respectively. The following invited talks were presented during the Workshop. Charge ordering and magnetism in half doped manganites. The role of Zener polarons. Juan Rodríguez Carvajal, Laboratoire Léon Brillouin, France Generation, Measuring Technique and Application of Pulsed Fields to Magnetism Roland Grössinger, Technical University of Vienna, Austria Characterization of Magnetic Fluids Paul Fannin, Trinity College Dublin, Ireland Novel Magnetic Materials Prepared by Electro Deposition Technique: Arrays of Nanowires and Bi-layer Microwires Manuel Vázquez, Instituto de Ciencias de Materiales (CSIC) Madrid, Spain Magnetic Field Induced Critical Behavior in the Hidden-Order Compound URu2Si2 Marcelo Jaime, National High Magnetic Field Laboratory - Los Alamos, U.S.A. Exchange bias in magnetic nanostructures Sergio Machado Rezende, Universidade Federal de Pernambuco, Recife, Brazil Giant Magnetoimpedance and Inductance Spectroscopy Raúl Valenzuela Monjarás, Instituto de Investigaciones en Materiales -UNAM Mexico Magnetism of U/Fe Multilayers Michael F. Thomas, University of Liverpool, U.K. 4d- and 5d-transition Metal Oxides: Nature’s Engineered Multi-layered Systems Jack Crow, National High Magnetic Field Laboratory - Tallahassee, U.S.A. Magnetoelectricity via crystallography Luis Fuentes Cobas, Centro de Investigación en Materiales Avanzados, S. C. Mexico First Principles Modeling of Magnetism and Phase Equilibria in Binary Alloys Alejandro Díaz Ortíz, Instituto Potosino de Investgación Científica y Tecnológica A.C., Mexico Review of High Strain Particulate Magnetostrictive Composites Greg P. Carman, University of California at Los Angeles, U.S.A. Magnetism at CIMAV José Matutes Aquino, Centro de Investigación en Materiales Avanzados, S. C. Mexico Materials Requirements for Terabit/in2 Magnetic Recording Ernesto Marinero, IBM Almaden Research Center, U.S.A. Non-Fermi-Liquid Behavior Induced by Antiferromagnetic Spin-Fluctuations Pedro Schlottmann, Florida State University, U.S.A. Mexico and the Early History of Magnetism Alberto Passos Guimaraes, Centro Brasileiro de Pesquisas Físicas, Brazil Magnetism and Magnetic Materials Research at Synchrotron Radiation Facilities in U. S.

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Chi-Chang Kao, National Synchrotron Light Source, Brookhaven National Laboratory, U.S.A. Neutrons as a Probe of Materials: Neutron Scattering Facilities in the U. S. Thomas Mason, Spallation Neutron Source, U.S.A. High Magnetic Fields: an Overview of World Facilities and Possible Opportunities for the Future Jack Crow, National High Magnetic Field Laboratory - Tallahassee, U.S.A. Ferrites and Oxides Roland Grössinger, Technical University of Vienna, Austria Opportunities for International Cooperation in Materials Research. An NSF Perspective Jack Crow, National High Magnetic Field Laboratory - Tallahassee, U.S.A. Carbon Nanotubes under high magnetic fields Bertrand Raquet, Laboratoire National des Champs Magnétiques Pulsés, Toulouse, France

Technical Sessions Two Technical Sessions took place simultaneously. “Rietveld Method” presented by Dr. Juan Rodríguez Carvajal and “Oxides and Ferrites” headed by Dr. Roland Grössinger. Participants chose the most adequate topic according to their interests. The duration of these Technical Sessions was 2 hours. Lively and often excited discussions between students and scientists favored the exchange of knowledge and experiences.

Poster Sessions 137 Abstracts were accepted for Poster Presentation. Three Poster Sessions exposed the latest developments in magnetic research. The first session was dedicated to Fundamental Magnetic Properties. The second session included soft and hard magnetic materials, magneto-electronic materials and instrumentation. The third session included magnetic films, multilayers, superconductors and interdisciplinary topics. An average of 20 posters were presented in each session. More than 70 manuscripts were received for publication, upon referee acceptance. The proceedings of the Workshop will be published as a special issue of the Journal of Alloys and Compounds (Elsevier).

Forum on International Collaboration Several well-known scientists from different countries directed the Forum. This Forum identified possible areas for mutually beneficial collaborations. It also led to the recommendation that extensive use of electronic communication for information exchange must be made to promote and facilitate research collaborations and educational activities. The VI LAW3M organizing committee offered their website to include a special place for international collaboration upon the recommendations of the Forum. Information about

23

institutions and scientists working on magnetism, subjects, scholarships, funding, collaborative program proposals, training courses, donation opportunities and special needs will be placed at this site. The site will be available at www.law3m.org.mx at least during one year. After this period, the site must be transferred to the VII LAW3M Organizers. The group leaders were: Dr. Roland Grössinger, Technical University of Vienna, Austria Dr. Luis Fuentes Cobas, CIMAV, Mexico Dr. Raúl Valenzuela Monjarás, Instituto de Investigaciones en Materiales -UNAM Mexico Dr. Vicente Sagredo, Universidad de Los Andes, Venezuela Dr. Greg P. Carman, University of California at Los Angeles, U.S.A. Dr. Ernesto Marinero, IBM Almaden Research Center, U.S.A. Dr. Fernando Luis de Araujo Machado, Universidade Federal de Pernambuco, Brazil

Symposium on International User Facilities in Support of Magnetic Related Research

This Symposium was organized by Dr. Jack Crow and sponsored by the National High Magnetic Field Laboratory. The main objective of the Symposium was to present the most important facilities for scientific research within the United States, mainly those related to magnetic research. It consisted on 4 lectures, 45 minutes long, explaining about facilities such as Synchrotron Radiation, Neutron Scattering and High Magnetic Fields. Additionally, opportunities for International Cooperation within the National Science Foundation were presented. Questions and comments about this report should be directed to Verónica Corral Flores at [email protected] or [email protected]. Address: Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109, Chihuahua, Chih. Mexico.

24

Results

25

26

27

Professors meeting in Merida (Venezuela):

Theoretical and Practical Workshop Inform Merida – Venezuela

June 9th – 14th, 2003 Centro de Estudios de Semiconductores

Physics Department, Science Faculty University of Los Andes, La Hechicera

Organization: The Theoretical part of the Workshop took place every morning from 09:00 am to 12:30 pm, from Monday to Friday. The courses were given by B. Raquet, J.M. Broto, and J. González. All the subjects in the program were developed (Program enclosed). In the afternoon took place the practical part ( 3-7pm) at the High Field Magnetic Pulsed laboratory of the Centro de Estudios de Semiconductores of Merida , the students were divided in groups of 6 and they made 3 lab practices with the participation of H. Rakoto, P. Bocaranda, Ch. Power, B. Raquet, J.M. Broto and J. González. The practices were:

- Colossal magnetoresistence in the thin film La2/3Ca1/3Mn03 (4–240 K, 0–20 T); - Magnetization function of B to study the order transition Sm0.475Sr0.525Mn03 (4 K,0–

20 T) - Handling of diamonds pressure cell and pressure scale: ruby luminescence Please find enclosed some magnetoresistence and magnetization Curves.

Participants: 25 students participate in the Workshop from Universities and other institutions of Venezuela: 02 – Universidad de Carabobo 03 – Universidad del Zulia 01 – Instituto Venezolano de Investigaciones Científicas (IVIC) 19 – Universidad de Los Andes Although, 10 Professors of our Department of Physics were enroll in the Workshop, for a total of 35 participants. Please find enclose pictures of the participants group and the Laboratory Expenses:

28

During the practices were used 500 liters of nitrogen and 50 liters of helium. Approximated costs: 2000,00 Euros. Course Program A) Transport Quantique sous champ magnétique :

I. Electrons sous champs intenses. 1- Hamiltonien 2- Densité d’état à 3 dimensions 3- Oscillations de Shubnikov de Haas 4- Densité d’état d’un système bidimensionnel 5- Introduction à l’effet Hall Quantique

II. Localisation d’Anderson.

1- Systèmes désordonnés- Etats localisés 2- Lois d’échelle de la localisation 3- Interférences quantiques –effets de la température et du champ magnétique sur

la résistivité

III. Propriétés de transport de nanotubes de carbone sous champ magnétique B) Magnétisme :

I. Introduction : Paramagnétisme-Ferromagnétisme localisé II. Ferromagnétisme de bande dans les métaux 3d III. Interaction RKKY dans les terres rares IV. Couches minces- Multicouches

1- Anisotropie magnétique 2- Domaines, parois 3- La magnétorésistance géante ( GMR) 4- Application à la lecture magnétique

29

Summer school in Toulouse (France) July 24th - 25th, 2003

“Advanced materials in high magnetic fields”

Network: HIFIELD Project number II0147FI

Agenda (proposal) 24th of July 9-10 Check-in 10 -10:30 Welcome session 10:30 – 11:30 R.Grössinger T.U.Vienna, “Report on ALFA activities” 11:30-12:30 Visit of LNCMP 12:30 – 13:30 Lunch

30

RECENT RESULTS ON ADVANCED MATERIALS

13:30 – 14 A. Penton, Havana University "High resolution x -ray diffraction studies in Sm(Co,Cu)5 alloys" 14-14 :30 J. Matutes, CIMAV Mexico “Magnetoelectric materials” 14 :30-15 V. Sagredo, Univ de los Andes, Merida “Magnetic properties of the

FeCr(2)Se(4) and Fe(2)CrSe(4) compounds ”. 15-15 :30 M. Costes, LNCMP Toulouse “Transport and magnetic properties in one

dimensional A’3ABO6 ”. 15 :30-16 J. Gonzales, ULA Merida “Nanocrystals of Cd0.5Mn0.5Te formed by the

pressure cycle method ”. 16 – 16:30 Coffee break 16:30-17 M.G.F. Vaz, Univ. Rio de Janeiro, “Recent results on advanced materials:

Molecular magnets“. 17-17:30 E. Snoeck, CEMES Toulouse, “Growth and characterization of magnetic thin

films”. 17:30-18 M. Novak, Univ. Rio de Janeiro, “Histeresis and magnetic relaxation in

nanomagnetic molecular structures.“ 18-18:30 L.O. Billoni, Univ Cordoba, “Cluster ferromagnetism in a partially amorphous

Nd60Fe30Al10 alloys”. 25th of July

MEASUREMENTS TECHNIQUES IN PULSED FIELDS 10-10:30 D. Vignolles, LNCMP Toulouse, “Cantilever magnetometry in pulsed

magnetic field“. 10:30-11 J. Gonzales, ULA Merida, “Electrical measurements under pressure in Bi up

to 6 GPa at 300 K“ .

31

11-11 :30 coffee break 11 :30 – 12 H. Bertorello, Univ Cordoba, “Development of a dual channel, 12-bit Data

Acquisition system for a pulsed Field magnetometer”. 12 – 12:30 R. Grossinger, TU Vienna, “Eddy Currents due to pulsed magnetic fields“ 12:30 – 13:30 Lunch 13:30 – 14 M.J.H. Espina Hernandez, Univ Habana, “New sensors in high pulsed

magnetic fields”. 14 -14:30 J.P. Sinnecker, Univ. Rio de Janeiro, “Time Dependent Magnetic Properties

In Thin Films: A combined use of Pulse Fields and Magneto-Optical techniques“.

14:30 -15 R. Sato, T.U. Vienna “ The influence of the magnetic viscosity on pulsed field

measurements”. 15 -15 :30 J. Matutes CIMAV Chihuahua “A magnetoelectric measurement technic in pulsed fields“ 15:30 - 17 Final discussion

32

Results

33

34

35

AUSTROMAG: PULSED MAGNETIC FIELDS BEYOND 40T

R.Grössinger, H.Sassik, O.Mayerhofer, E.Wagner, M.Schrenk Inst. f. Solidstate Physics, Techn. Univ. Vienna, Wiedner Hauptstr. 8-10, Vienna, A-1040 Austria

Elsevier use only: Received date here; revised date here; accepted date here

Abstract

The aim of this work is to describe the further development of the presently existing quasistatic high field facility reaching 40T in a long pulse (1s). In order to achieve fields up to 70T in the future a two coil system will be constructed, where a short pulse (about 5ms) of 30 to 40 T will be generated in a small inner coil, which will be additive to a 30T long pulse. The currently available parts of the existing machine (Austromag) as well as the experience on this area will be used. Beside the increase of the available field the extension of our measurement methods will be described. This covers the development of a pressure cell as well as developments of magnetization measurement systems with improved sensitivity (vibration method, surface coils, cantilever) which are just under construction. © 2001 Elsevier Science. All rights reserved Keywords: High magnetic fields, pulse magnets PACS number 07.55

Submitted to Elsevier Science 36

A

TiTw

KP

The design and construction of a thin foil high field magnet

R.Grössingera, F.Keplingerb, H.Hauserb

aInstitut f. Festkörperphysik, T.U.Vienna, Wiedner Hauptstr. 8-10, A-1040 Austria

Institut f. Industrielle Elektronik, T.U.Vienna, Wiedner Hauptstr. 8-10, A-1040 Austria

Elsevier use only: Received date here; revised date here; accepted date here

bstract

he design and construction of a new type of high field magnet is described. The conductor is a thin (0.15 mm) Cu-foil which s separated by a 12 µm Hostaphan foil. The magnet was designed electrically as well as the mechanical stress was estimated. he design shows that this magnet should produce fields up to 35 T with our Austromag system (10 MW for 1s). First tests ere performed using a 24 mF capacitor bank.

© 2001 Elsevier Science. All rights reserved

eywords: High magnetic fields, pulse magnets ACS number 07.55

37

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