AD-A241 490I IIIIl11111lii'lI PREFACE

In the last twenty years a great amount of progress has been made in the development of new

magnetic materials. Permanent magnets have progressed from the AINiCo's (with (BH)m-8 MGOe)

to the strong rare-earth magnets of SmCo5 ((BH)m~20 MGOe), Sm 2(Co,Fe,Cu,Zr) 17 ((BH)m-30

MGOe) and the recently discovered Nd-Fe-B super-magnets with (BH)m-50 MGOe. For years the

magnetic storage industry has employed Fe2 0 3 and Cr0 2 for storage media and permalloys and

ferrites for recording heads. The recent development of thin film heads, the demand of higher

density of information storage and the emergence of completely new technologies, like magneto-

optics, call for entirely new types of magnetic materials. Another area in which new techniques of

materials preparation have made a dramatic impact is the epitaxial growth of magnetic films. Recent

work has shown that this process can be controlled on the scale of atomic monolayers permitting the

growth of totally artificial structures, such as artificial superlattices with a resolution on this scale.

Epitaxial growth has also permitted the stabilization of metastable phases in thin film form. These

new phases often possess striking properties, such as strong perpendicular anisotropies, which may

prove useful for technological applications such as recording. Research on magnetic multilayers and

superlattices is increasing at an accelerating pace. Complex couplings between different magnetic

layers lead to new properties not secn in bulk materials. Magnetic surfaces and interfaces show large

magnetic anisotropy (surface anisotropy), coercivity, galvano-magnetic and magneto-optic effects that

can lead to future storage technologies. Ultrafine particles also show interesting and unique properties

ranging from superparamagnetism to strong magnetic hysteresis in particles with a size close to that

of single domain particle. The investigation of these new materials is shedding new light on

magnetism in general, and yields unusual materials in powder form which have potential use in

magnetic tapes as well as in many other technological areas.

The remarkable progress made in magnetic materials has been aided by an interplay between

experimental measurements and theoretical models. The Stoner and Wohlfarth model of single domain

particles helped significantly in understanding the origin of magnetic hysteresis in permanent

n2-tz ,- ',,"ever, this oversimplif;ed theory is often used incorrectly to describe the hysteresis

91-11632

behavior of complex magnetic materials where a "domain wall pinning" or a "nucleation of reversed

domains" process is rather more appropriate. The origin of surface anisotropy in thin films and

ultrafiuce particles is not yet clear, and the effects of film thickness and interfaces on the intrinsic and

extrinsic magnetic properties are not well understood. In superlattices, it is now found that strong

coupling between two ferromagnetic layers can be carried through an intervening layer which is not

ferromagnetic. Transport measurements in these structures show giant magneto-resistance effects.

The progress in band theory of magnetic materials has also been remarkable. Using novel statistical

techniques of Monte Carlo calculation the Curie temperature of Fe has been calculated accurately.

This progress has now paved the way for addressing the important "secondary" phenomena such as

magnetic anisotropy, galvano-magnetism and magneto-optic rotations which are due to "spin-orbit

coupling." All of these properties have been poorly understood in the past and are decisive for many

application.

The NATO Advanced Study Institute (ASI) on the Science and Technology of Nanostructured

Magnetic Materials which was held June 24 - July 6, 1990 in Agh'a Pelaghia, Crete, Greece, reviewed

the remarkable progress made in magnetic materials over the !ast few years and adres:ed the current

state-of-the-art research and its impact on technological applicaticna. The subject matter fell into

a number of broad areas including thin films, multilayers, disordered systems, ultrafine particles,

intermetallic compounds, permanent magnets and magnetic imaging techniques. The present volume

contains the invited lectures as well as a number of contributed papers. The book is divided into

seven chapters representing the various topics discussed at the meeting. We hope that this book will

serve as a reference to all researchers in magnetic materials and other reiated fields.

The workshop was made possible due to the generous support by NATO Scientific Affairs

Division, Brussels, Belgium. The directors wish also to express their gratitude for the additional

support by the Office of Naval Research, European U. S. Army, IBM, General Electric, Philips

Hamburg and Du Pont. We also thank Mrs. Helen Long for her efficient assistance with many aspects

of the workshop and Mrs. Voula Hadjipanayis for her enthusiastic support during the time of the

meeting.

George C. Hadjipanayis

Gary Prinz

CHAPTERS

I. Thin Films, Surfaces and Interfaces

II. Multilayers

III. Domain Walls, Magnetic Domains and Techniques for Their Observation

IV. Magnetic Anisotropy and Random Magnets

V. Magnetic Semiconductors and Intermetallic Compounds

VI. Fine Particles

VIL Magnetic Hysteresis and Permanent Magnets

4 . 4/I

4/

I. THIN FILMS, SURFACES AND INTERFACES

1. Electronic Structure and Magnetism of Metal Surfaces, FreemanOverlayers & Interfaces

*2. Metastable Phases Via MBE G. Prinz

3. Spin Resolved Photoemmision Kirschner

4. Growth and Magnetic Properties of Metastable HeinrichStructures

5. Correlation of Crystalline and Electronic Structure in SchneiderEpitaxial FCC-Cobalt Monolayers on Cu(100)

6. M6ssbauer Studies of Ultrathin Magnetic Films of KoonFe/Ag(l00)

7. Spin-Dependence of Absorbed and Reflected Current Hammondon Fe(l 10)

8. MBE Growth of Metal/Semiconductor Interfaces Slaughter

9. Surface and Interface Magnetism Meier

10. Ferromagnetic Resonance Studies of Epitaxial CelinskiUltrathin Fe(001)/Cu(001) Bilayers andFe(001 )/Cu(001 )/Fe(001) Trilayers

11. Laser Ablation Deposition of Metallic Thin Films Gavigan

12. Exchange Coupled Films for Magneto-Optic GambinoApplications

13. Temperature Dependence of Micromagnetic Domain McFadyenStructure in Cobalt Films

14. Hyperfine Interaction Techniques Applied to the Study Rots

of Surfaces and Interfaces

15. Surface Magnetostriction O'Handley

* to be s 2:7-.ct!,., to Plennum Publishing Company

II. MULTILAYERS

1. Magnetic Rare-Earth Artificial Metallic Superlattices Rhyne

2. X-Ray Characterization of Magnetic Multilayers and FalcoSuperlattices

3. The Characterization of Interface Roughness and SinhaOther Defects in Multilayers by X-Ray Scattering

4. Magnetism of Nanostructured Rare-Earth Multilayers Sellmyer

5. FMR Studies of Metalic Magnetic Thin Films in HurdequintLayered Structures

6. Compositionally Modulated Magnetic Multilayers: FlevarisTemperature and Modulation Dependent Properties

7. Structural and Magnetic Properties of Epitaxial Co/Pd EngelSuperlattices

8. First Principle Calculation of the Magnetocrystalline DaalderopAnisotropy Energy of ConPdm Multilayers

9. Structural and Magnetic Studies in Co-Pt Multilayers Krishnan

10. Magnetic Properties of Hexagonal Fe/Ru Superlattice PiecuchWith Short Periodicities

1]. Magnetic Studies of Fe-Si Compositionally Modulated Te jada

Thin Films

12. M6ssbauer Spectroscopy of the Fe/Ni Interface Donzelli

13. Analysis of Amorphous Dysprosium - Transition Metal ShanNanoscale Magnetic Multilayers

14. Transport Properties of Metallic Thin Films and FertMultilayers

6

III. DOMAIN WALLS, MAGNETIC DOMAINS AND TECHNIQUES FOR THEIR OBSERVATION

1. Micromagnetics of Longitudinal Recording Media Alexopoulos

2. MO-Recording: The Switching Process and Its MergelRelation to the Magnetic Properties of Thin Films

3. Micromagnetic Computations of Magnetization JakubovicsConfigurations

4. Domain Walls and Domain Wall Structure Humphrey

5. Domain Wall Multiplication in Amorphous BeatriceFerromagnetic Alloys

6. Electron Microscope Methods for Imaging Internal SpenceMagnetic Fields at High Spatial Resolution

7. Scanning Tunneling Microscopy and Force Microscopy GarciaApplied to Magnetic Materials

8. Special Session on Spin-Polarized Vacuum Tunneling Notes by Hathaway

9. Magnetic Imaging Via Scanning Electron Microscopy Celottawith Polarization Analysis

10. Atomic Scale Probe Into High-Tc Superconductors RaoUsing Scanning Tunneling Microscopy

7

IV. MAGNETIC ANISOTROPY AND RANDOM MAGNETS

1. Magnetic Anisotropy Jansen

2. Random Anisotropy in Magnetic Materials Cullen

3. Perpendicular and In-Plane Anisotropy in Amorphous O'SheaTb-Fe

4. Magnetostriction in Amorphous Magnets Hernando

5. Anderson Localization in 3-Dimensional Amorphous FilippiAlloys: Evolution with the Content of Magnetic Ions

6. On the Law of Approach to Saturation in the Series of AmaralAmorphous Alloys oc-Dy.Gd 1-. Ni

7. Magnetoresistance of Amorphous Ul xSb x Films Freitas

8. Absence of Temperature-Driven First Order Phase BerkerTransitions in Systems with Random Bonds

V. MAGNETIC SEMICONDUCTORS AND INTERMETALLIC COMPOUNDS

1. Magnetic Behavior of Diluted Magnetic de JongeSemiconductors

2. Intermetallic Compounds and Crystal Field CoeyInteractions

3. Crystal Field and Exchange Interactions in Hard FranseMagnetic Materials

4. First Order Magnetization Processes Asti

5. Structure and Properties of Novel Ternary Fe-RichRare-Earth Carbides Jacobs

9

ib

VI. FINE PARTICLFS

1. Granular Solids Chien

2. Ultrafine Magnetic Particles Hadjipanayis

3. Magnetic Nanometer Systems and M6ssbauer MorrishSpectroscopy

4. Some Topics in Fine Particle Magnetism Berkowitz

5. M6ssbauer Studies of Fine Fe-Based Particles Morup

6. M6ssbauer Studies of Fine Partizles of Fe-Cr-B Kostikas

7. Chemical Preparation of Fe-Cr-B Particles Koch

8. Composition and Structure of Fe-Ni-B Alloy Particles LinderothPrepared by Chemical Reductions with NaBH 4

9. Quantum Effects in Ultrafine Nd-Fe-B Particles Quintela

10. Magnetization Revrsal in Clusters of Magnetic HendriksenParticles

11. Electric and Magnetic Properties of Small Systems Arajs

12. Existence of Frequency Cut-Off in the Spin Wave GarciaSpectrum of Small Magnetic Particles

10

VII. MAGNETIC HYSTERESIS AND PERMANENT MAGNETS

1. Mechanically Alloyed Permanent Magnets Schultz

2. Melt-Spun Magnets Pinkerton

3. solid NdFeB Magnets Made by Gas Atomization and DulisExtrusion

4. The Role of Microstructure in Permanent Magnets Hadjipanayis

5. Lorentz Microscopy in Permanent Magnets Fidler

6. Coercivity in Hard Magnetic Materials Givord

7. Micromagnetism and Magnetization Processes in KronmUiherM dern Magnetic Materials

8. Micromagnetic Approach to Magnetic Hysteresis Victora

9. Magnetic Hysteresis in Disordered Magnets Soukoulis

10. Coercivity of Nanostructured Materials Otani

11. Magnetic Hysteresis of Co-Pt Films Tsoukatos

12. Technology and Application of Permanent Magnets Narasimhan

II

Asued Apl 1988 ASI no.

NATO International Scientifi-- Exchange Programmes

ADVANCED STUDY INSTITUTEScientific Affairs Disor- NATO B 1110 Brussers Beigium -e";4-'r1 0 - 2 7 (NATOH'd.,-)

GENERAL REPORT

Note

This report should be sent within 30 oays of the meeting. The financial report (pink form) may be sent later after consolidation of theaccounts, however it must be with NA TO by not later than 120 days from the end of the meeting. It should be recalled that only afteracceptance by NA TO of the financial report as wcll as the present report can any final supplementary award be authorized.

1. Advanced Study Institute

Title: Science and Technology of Nanostructured Magnetic Materials

Location: Aghia Pelaghia Dates: June 25 - July 6, 1990

(site and country) Crete, GREECE Number of working days: 10

2. Director:(name, positio, official address, telephone no. telex no.)

George C. Hadjipanayis

Professor of Physics

University of DelawareNewark, DE 19716(302)451-2736

3. Principal Members of the Organizing CommitteeIname, position, official address)

Dr. Gary Prinz, Naval Research Lab, Washington, DC 20375-5000Dr. Luigi Paretti, MASPEC, Parna, ITALY

Code % Code % Code %

4. Scientific Codes and percentages of M4JI I4 1 I21i1iE2IIE L L.IiL.L-discipline content (see NATO classificationof scientific subjects)

2

5. Gen.,ral Comments

The Director i- asked to give here general con,,'"ents on the meetiny ; conments on the application process, theplanning and execution of the meeting itself and follo% -up are also useful for the maintenance and improvement of theASI Programme and are welcome. Specifically financial comments should not be given here but may be made in theaccompanying financial report. A short scientific summary of the meeting should be pepared on the attached cameraready copy sheets for publication in the NATO Science Committee Yearbook.

The idea for a NATO Advanced Sti, qstitUW on Nanostructured Magnetic Materialsarose in 'a 3M Conference where y Prinz suggested to me that we should holdthis Institute in Greece. Soon arter this we planned a tentative program, madea list of posible lecturers and wrote to them asking if they wanted to participatein the Institute. After we received their answer we applied to NATO for fundingof the Institute.

When we learned thai the proposed Institute was approved we wrote again to thelecturers, reminded them of their duties and asked them, to provide us with namesof good ctudents who would greatly benetit from this Institute. We also sentletters and posters to many laboratories doing research in magnetic materialsand encouraged researchers and students to apply for the Institute. In add'tionwe advertised the Institute in the Physics Today andA large number of students and researchers applied to come to the Institute. Atthis time we decided to include Pdditional short talks to ccver the state-of-theart current research in magnetic m-terials. We have chosen several speakersfrom the people who applied and asked them to give "invited talks" on topics oftheir expertise. These speakers were treated the same way as the other partic-ipants. We also advertised the idea of poster presentations.

Several times before the meeting we sent letters to the lecturers and speakersand ask them to have their manuscripts ready at the time of the Institute andalso copies and summaries of the talks for the rest of the participants.Tentative lists of participants were sent to Plenum Publishing Company, whoprovided camera ready sheets and instructions for manuscript preparation toall applicants. The daily program consisted of talks frcm 8:45 a.m. to 10:45 a.m.followed by a coffee break at 11:15. Tho talks continued until 1:15 p.m. followedby a siesta to 5:00 p.m. The talks resumed again at 5:00 to 7:00 p.m. afterwhich lie group got together for dinner. During the time of the meeting it wasevident that some topics needed additional time for questions to be answered anddifferences to be resolved. To handle this we introduced special sessioas, forthose interested, in the afternoon at 4 F.m., one hour before the afternoonsession.

Wednesday afternoon we visited Knossos and on the first Sunday we organizedan excursion to Samaria Gorge. Our social events included a welcome cocktailparty, a Greek night and a banquet Cretan night.

3

6. National distribution of Lecturers (L) and ASI Students (S)

L S L S L S L S

Belgium Iceland Spain 1 Other CountriesCanada 1 Italy Turkey (specify)Denmark Luxembourg UK 1 IrelandFrance 2 Netherlands 2 USA 5

Germany 2 NorwayGreece 1 Portugal TOTALS

7. Book to be published as a product of the ASI

Title of Book: SCIENCE AND TECHNOLOGY OF NANOSTRUCTURED MAGNETIC MATERIALS

Editor(s) : (a) George C. Hadjipanayis

(b) Gary Prinz

(c) Luigi Pareti

Publisher: Plenum Publishing Company

Expected Date of Publication: April 1991

Editor's Comments

Date: S. Signature gA.(q

At~achments

1. Annex - List of Director(s), Lecturers and ASI Students2. Scientific summary : camera ready

June 25 - July 6, 1990Heraklion (Aghia Pelayia) Crete, Greece

Dr. George C. HadjipanayisDept. of Physics & AstronomyUniversity of Delaware, Newark, DE 19716

The Institute reviewed the remarkable progress made in magnetic materials over thelast few years and addressed the current state-of-the-art research and its impact ontechnological applications. The subject matter fell into a number of broad areas includingthin films, multilayers, disordered systems, ultrafine particles, intermetallic compounds,permanent magnets and magnetic imaging techniques.

The development of new techniques for materials preparation has made a dramaticimpact in the area of epitaxial growth of magnetic films. Several presentations have shownthat this process can be controlled on the scale of atomic layers permitting the growth ofartificial structures such as artificial superlattices with nearly atomir resolution. Epitaxialgrowth has also permitted the stabilization of metastable phases in thin films which oftenpossess a strong perpendicular anisotropy which may prove useful for technologicalapplications. In magnetic multilayers and superlattices the complex coupling betweendifferent magnetic layers was discussed both experimentally and theoretically. In superlatticesit was proposed that a strong coupling between two ferromagnetic layers can be carried outthrough an intervening layer which is not ferromagnetic. This coupling leads to newproperties not seen in the past. Magnetic surfaces and interfaces show large magneticanisotropy (surface anistropy), coercivity, magnetoresistance, galvanomagnetic andmagnetooptic effects that can lead to future storage technologies. Band structure studies usingstaiistical techniques of Monte Carlo calculations, led to accurate calculations of the Curietemperature of Fe, Co, Ni films. The solution of this problem opened the door for otherimportant phenomena which are due to "spin orbit" coupling. Several contributions discussedthe physics of ultrafine particles and granular solids with interesting and unique propertiesfrom superparamagnetism to strong magnetic hysteresis. The magnetic properties of rare-earth intermetallic compounds with potential applications in permanent magnets have beendiscussed including the crystal field effects and the origin of magnetic anisotropy. Themagnetic hyste 2sis behavior of fine particles, permanent magnets, melt-spun ribbons andmechanically alloyed magnets have been discussed. The magnetic hysteresis models of"domain wall pinning" and "nucleation of reversed domains" have been reviewed and theirapplicability in different magnetic materials was discussed. The micromagnetic approachusing the Landau-Lifshitz-Gilbert equation was also presented to explain the hysteresisbehavior of thin films.

The magnetic properties of all of these materials are strongly influenced by theirmicrostructure and several methods to evaluate their growth, lattice structure and sampleintegrity were discussed. These included spin-polarized electron spectroscopy, DPC andRHEED/RE Microscopy and Lorentz microscopy.

Finally the applications of magnetic materials in magnetic recording, magneto-opticrecording and permanent magnets have been discussed with more emphasis given to theimprovement of material properties for these applications.

Granular Solids, Prof. C. Chien, Johns Hopkins University, Baltimore, MarylandIntermetallic Compounds and Crystal Field Interactions, Prof. T. Coey, Trinity College,

Dublin, IrelandRandom Anisotropy in Magnetic Materials, Prof. J. Cullen, Naval Surface Weapons Center,

Silver Springs, MDMagnetic Behavior of Diluted Magnetic Semiconductors, Prof. W. de Jonge, Eindhoven

University of Technology, The NetherlandsTransport Properties of Metallic Thin Films and Multilayers, Prof. A. Fert, Universite Paris

Sud, Orsay, FranceScanning Tunneling Microscopy and Force Microscopy Applied to Magnetic Materials, Prof.

N. Garcia, Autonouous University of Madrid, Madrid, SpainCoercivity in Hard Magnetic Materials, Prof. D. Givord, Neel Laboratory, Grenoble, FranceUltrafine Magnetic Particles, Prof. G. C. Hadjipanayis, University of Delaware, Newark,

DelawareThe Role of Microstructure in Permanent Magnets, Prof. G. C. Hadjipanayis, University of

Delaware, Newark, DelawareMicromagnetism and Magnetization Processes in Modern Magnetic Materials, Prof. K.

Kronmiller, Max-Planck Institute fur Metallforschung, Stuttgard, GcrmanyMagnetic Nanometer Systems and M6ssbauer Spectroscopy, Prof. A. Morrish, University of

Manitoba, Winnepeg, CanadaMetastable Phases Via MBE, Dr. G. Prinz, Naval Research Laboratory, Washington, D. C.Magnetic Rare-Earth Artificial Metallic Superlattices, Prof. J. Rhyne, National Bureau of

Standards, Gaithersburg, MarylandSpin Resolved Photoemmision, Prof. J. Kirschner, Institut fur

Grenzflachenforschung and Vakuumphysik, Julich, GermanyMagnetism of Nanostructured Rare-Earth Multilayers, Prof. D. Sellmyer, University of

Nebraska, Lincoln, NebraskaElectron Microscope Methods for Imaging Internal Magnetic Fields at High Spatial

Resolution, Prof. J. Spence, Arizona State University, Tempe, Arizona

G. C. Hadjipanayis, University of Delaware, USA (Director)G. A. Prinz, Naval Research Lab, USA (Secretary and Editor)L. Parett;, MASPEC Institute, Italy (European Editor)

Plenum Publishing Corporation

LECTURERSProfessor J. Kirschner

Professor C. Chien Institut fur GrenzflachenforschungJohns Hopkins University and VakuumphyiskDepartment of Physics KFA JulichBaltimore, MD 21218 WEST GERMANY

Professor T. Coey Professor K. KronmullerDepartment of Pure & Applied Physics Max-Planck Inst. fur MetallforschungTrinity College Institut fur PhysikDublin 2 Heisenbergstrasse IIRELAND 7000 Stuttgard 80

WEST GERMANYProfessor J. CullenNaval Surface Weapons Center Professor A. MorrishSilver Springs, MD 20901-5900 Department of Physics

University of ManitobaProfessor W. deJong Winnepeg, MAN R3T 2N2Department of Physics CANADAEindhoven University of Technologyde Dolech 2 Dr. G. PrinzNL-5600 MB Eindhoven Naval Research LaboratoryNETHERLANDS Washington, DC 20390

Professor A. Fert Professor J. RhyneLaboratoire de Physique des Solides National Bureau of Standards

Universite Paris Sud Gaithersburg, MD 20899F91405 Orsay, FRANCE

Professor D. SellmyerProfessor N. Garcia Department of PhysicsDepartment of Physics University of NebraskaAutonouous University of Madrid Lincoln, NE 68588Madrid, SPAIN

Professor J. SpenceProfessor D. Givord Department of PhysicsNeel Laboratory Arizona State UniversityCNRS 166X-38042 Tempe, AZ 85287Grenoble, CEDEXFRANCE

Professor G. HadjipanayisUniversity of DelawareDepartment of Physics & AstronomyNewark, DE 19716

Professor H. JansenDepartment of PhysicsOregon State UniversityCorvallis, OR 97331

SEpEAKER$

Professor V. Amaral Dr. 0. Donzelli

Centro de Fisica de Universidade Dipartimento di Fisica

de Porto Universita (GNSM-CISM)

4000 Porto via Paradiso 12

PORTUGAL 44100 FerraraITALY

Dr. P. AlexopoulosIBM Almaden Research Center Dr. E. Dulis

650 Harry Road Crucible Research Inc.

San Jose, CA 95120-6099 Pittsburgh, PA 15212

Dr. S. AraJs Dr. C. Falco

Department of Physics Optical Science Center

Clarkson University & Physics Dept.

Potsdam, NY 13676 University of ArizonaTucson, AZ 85721

Dr. G. AstiInstitute MASPEC del C.N.R. Dr. J. Fidler

via Chiavari, 18 A, 43100 Parma Technical Universitat Wien

ITALY Wiederer Hausptstrasse 8-10A-104 Wien

Dr. N. Berker AUSTRIAMITPhysics Department Professor P.J.P. Freitas

Cambridge, MA 02139 INESC, rua Alves Redol 9Apartado 10105

Dr. A. Berkowitz 1017 Lisboa Codex

Mail Code R-001 PORTUGALCenter for Magnetic RecordingUniveristy of CA - San Diego Dr. J. J. M. Franse

La Jolla, CA 92093 Natuurkunding LaboratoriumUniversity of Amsterdam

Dr. R. Celotta Valckenierstraat 65

National Institute of Science 1018 XE Amsterdam

& Technology THE NETHERLANDS

Gaithersburg, MD 20899Dr. R. J. Gambino

Dr. Daalderop IBM

Philips Research Lab Thomas J. Watson Research

Eindhoven Yorktown Heights, NY 10598

THE NETHERLANDSDr. J. Gavighan

Dr. J. Dekoster Neel Laboratory

Celestunenlaan 200-D CNRS 166X-38042

B 3030, Leuven, BELGIUM Grenoble, CEDEXFRANCE

Dr. B. Heinrich Dr. F. MeierPhysics Department Laboratorium FestkorperphysikSimon Fraser University ETH HonggerbergBurnaby, BC, CANADA CH-08093 Zurich

SWITZERLANDDr. A. HernandoLaboratoire de Magnetismo Dr. D. MergelFacultad de C Fisicas Philips Research LabUniversity Completense D-2000 Hamburg 5428040 Madrid, SPAIN POB 540840

GER .'_AYDr. K. HowardDepartment 72/028 Dr. S. MorupIBM Laboratory of Applied Physics5600 Cottle Road of Denmark

San Jose, CA 95193 DK-2800 LyngbyDENMARK

Dr. F. HumphreyBoston University Dr. K.S.V.L. NarasimhanP.O. Box 722 Hoeganaes MagneticsMeredith, NH 03253 65 Indel Avenue

Rancocas, NJ 08073

Dr. H. HurdequintLaboratoire de Physique Dr. R. O'Handley

des Solides MITUniversite Paris Sud 77 Massachusetts Avenue91405 Orsay Cambridge, MA 02139FRANCE

Dr. M. O'SheaMrs. T. H. Jacobs Department of PhysicsKamerlingh Onnes Lab Cardwell HallUniversity of Leiden Kansas State University

2300 RA Leiden Manhattan, KS 66506THE NETHERLANDS

Dr. M. PiecuchDr. J. P. Jakubovics Laboratoire MixteDept. of Metallurgy & Science CNRS-Saint Gobain

of Materials CRPAM-BP 109University of Oxford 54704 Pont-A-Mousson CEDEX

Parks Road, Oxford OXI 3PH FRANCEENGLAND

Dr. F. E. PinkertonDr. N. Koon Physics DepartmentNaval Research Lab General Motors Research Labs

Washington, D.C. 20375 Warren, MI 48090-9055

Dr. T. KostikasDemokritos National Research Center Dr. J. Rivas

Institute of Materials Science Depto. Fisica Applicada153 10 Ag. Paraskeri Attikis Facultad de Fisica

P.O.B. 60228 E-15708 Santiago de CompostelaGREECE SPAIN

Dr. M. Rots PARTICIPANTSInstituut voor Kern-en StrakingsfyskaKatholieke Universiteit Professor V. AmaralLeuven, BELGIUM Centro de Fisica de Universidade

de PortoDr. L. Shultz 4000 PortoSiemens, AG Research Labs. PORTUGALD-8520 ErlangenFEDERAL REPUBLIC OF GERMANY Professor F. Badia

Dept. de Fisica FonamentalProfessor K. V. Rae Universitat de BarcelonaDepartment of Solid State Pivsics Diagonal 647Royal Institute of Technology E-08028Stockholm, SWEDEN SPAIN

Dr. C. Soukoulis Dr. T. BakasDepartment of Physics Univeristy of loanninaIowa State University P.O.B. 1186Ames, IA 50010 OR-451 10 Ioannina, GREECE

Dr. J. Tejada Mr. C. BallentineFacultad de Fisica MIT, Rm. 4-015Universidad de Barcelona Cambridge, MA 02139Diagonal 647.08028SPAIN Professor C. Beatrice

Instituto Elettrotecnico NazionaleProfessor T. Tsakalakos Galileo FerrarisRutgers University c.So D'Azeglio 42Department of Materials Science 10125 TorinoP.O. Box 909 ITALYPiscataway, NJ 08854

Mr. P. BelienUniversity of Leuven

Dr. R. H. Victora Department of PhysicsDiversified Technologies Div. Celestijnenlaan 200 DResearch Laboratories B-3030 Leuven, BELGIUMEastman Kodak Co.Rochester, NY 14650 Mr. M. Carey

Center for Magnetic Recording Res.Univ. of California, San DiegoLa Jolla, CA 92093

Dr. Z. CelinskiDepartment of PhysicsSimon Fraser UniversityBurnaby VSA IS6BRITISH COLUMBIA

Mr. J. ChildressJohns Hopkins UniversityDepartment of PhysicsBaltimore, MD 21218

Mr. J. GuzmanMr. C. Christides Magnetics Technology CenterInstitute of Materials Science Carnegie Mellon UniversityDEMOKRITOS N.R.CPS Pittsburgh, PA 15213Ag. Paraskevi, Attiki, GREECE

Mr. L. GiordanoDr. A. Clark Centro AtomicoNaval Surface Weapon Center 8400-BarilocheSilver Spring, MD 20903 ARGENTINA

Mr. J. Costa Kramer Dr. J. GonzalezDepartment of Solid State Physics Inst. de Ciencia de MaterialesRoyal Institute of Technology C.S.I.C.S-10044, Stockholm, SWEDEN Serrano 144 28006

Madrid SPAINProfessor R. DayCsiro Applied Physics Professor M. HammondPO Box 218 Freie Universitat BerlinLindfield NSU 2070 Fachbereich PhysikAUSTRALIA Institut fur Arom under

Festkorperphysik (WE-l)Mr. B. Engel Arnimallee 14, D-1000 BerlinDepartment of Physics FEDERAL REPUBLIC OF GERMANYUniversity of ArizonaTucson, ARIZONA 85721 Dr. M. Hanson

Physics DepartmentDr. J. Filippi Chalmers University of TechnologyLaboratoire Louis Neel S-412 96 Goteborg, SWEDENC.N.R.S.166X, 38042 Dr. K. HathawayGrenoble, CEDEX Code 1114FRANCE Office of Naval Research

800 N. Quincy StreetDr. N. Flevaris Arlington, VA 22217Solid State PhysicsAristotelio University of Thesaloniki Mr. P. Hendriksen54006, Theloloniki Lab. of Applied PhysicsGREECE Tech. Univ. of Denmark

DK Lyngby, DENMARKProfessor G. FratucelloUniversita di Ferrara Mr. D. HurleyDepartmento di Fisica Dept. of Pure & Applied Physicsvia Paradiso 1-44100 Trinity CollegeFerrara, ITALY Dublin 2, IRELAND

Mr. A. Garvin Professor R. KrishnanDepartment of Physics & Astronoy Laboratoire de Magnetisme CNRSJohns Hopkins University 92195 Meudon CEDEXBaltimore, MD 21218 FRANCE

Dr. S. Linderoth Dr. D. NiarchosLab. of Applied Physics Demokritos National Research CenterTechnical University of Denmark 153 10 Ag. Paraskeri AttikisDK-2800, Lyngby P.O.B. 60228DENMARK GREECE

Dr. R. McCallum Mr. J. NoguesAmes Lab, 106 Wilhelm Hall Department of Solid St. PhysicsIowa State University Royal Inst. of Tech.Ames, IA 50011 S-100 44, Stockholm, SWEDEN

Dr. I. McFadyen Dr. M. OlivieriaIBM Research Division MIT-Department of PhysicsAlmaden Research Center 77 Massachusetts Avenue650 Harry Road Cambridge, MA 02139San Jose, CA 95120-6099

Dr. Y. OtaniProfessor B. Martinez Trinity CollegeDept. de Fisica Fonamental Department of Pure & Applied PhysicsUniversitat de Barcelona Dublin 2, IRELANDDiagonal 647E-08028 Barcelona Dr. V. PapefthymiouSPAIN Demokritos NptiLail Research Center

Insbt. of Materials ScienceMs. N. Karaoglu 152-3 10 Ag. Paraskeri AttikisDakuz Eylui University P.O.B. 60228Engineering Architectural Faculty GREECEGeological Engineering 35100Bornova/Izmir, TURKEY Dr. F. Petroff

Laboratoire de Physique des SolidesMr. C. Koch Univesite Paris-SudLab. of Applied Physics 91405 OrsayBldg. 307 FRANCETech. Univ. of DenmarkDK-2800 Lyngby, DENMARK Dr. D. Polk

Materials DivisionMs. K. Mahoney Office of Naval ResearchR43 Naval Surface Warfare Center 800 N. Quincy StreetSilver Spring, MD 20905-5000 Arlington, VA 22217

Professor C. Mavroyamnnis Ms. M. PontDivision of Chemistry Departamento de FisicaNational Research Council of Canada Universitat Autonoma BarcelonaOttawa, Ontario, Canada KlA OR6 08193 Bellaterr SPAIN

Dr. L. Melo Professor P. PoulopoulosINESC Department of PhysicsR. Alves Redol, 9-3 Aristotle University of ThessalonikiP-1O00 Lisboa, PORTUGAL Thessaloniki, GREECE

Professor E. Ribas Mr. E. SingletonDept. de Fisica Fonamental University of DelawareUniversitat de Barcelona Dept. of Physics & AstronomyDiagonal 647, E-08028 SPAIN 223 Sharp Lab08028 Barcelona, SPAIN Newark, DE 19716

Dr. J. Schmidt Dr. S. SinhaInst. de Fisica-UFRGS Physics DepartmentCx. Postal 15051 Brookhaven National LabPorto Alegre, RS 91500 BRAZIL Upton, NY 11973

Professor C. Schneider Mr. S. SladeFreeie Universitat Berlin University of California-San DiegoFachbereich Physik Center for Magnetic RecordingInstitut fur Atom under R-001

Festkorperphysik (WE 1) La Jolla, CA 92093Arminallee 14, D-1000Berlin 33 Dr. J. SlaughterFEDERAL REPUBLIC OF GERMANY Department of Physics

Building 81Dr. I. Shah University of ArizonaE. I. duPont Experimental Station Tucson, AZ 85721P.O. Box 80356Wilmington, DE 19880-0356 Dr/. M. Solzi

Ivistituto Materiali Speciali

Mr. Z. Shan Per Elettronica E. MagnetismDept. of Physics & Astronmy MASPECBehlen Lab 43100 Parma, ITALYLincoln, NE 68588

Professor J. SousaDr. B. Siberchicot Centro de Fisica de Universidade deBoite Postale 27 Porto94190-Villeneuve St. Georges 4000 PortoFRANCE PORTUGAL

Dr. W. Simmons Professor C. StassisChief Materials Branch Iowa State UniversityU.S. Army Research Department of PhysicsDevelopment & Standardization Group Ames, IA 50011Edison House, 223 Old Marylebone Rd.London NW11 5th Dr. J. TeterENGLAND R43, Naval Surface Warfare Center

Silver Springs, MD 20905-5000Dr. T. SimopoulosDemokritos National Research Center Dr. F. TezerInst. of Materials Science Physics Department153 10 Ag. Paraskeri Attikis Hacettepe UniversityP.O.B. 60228 Beytepe, AnkaraGREECE TURKEY 06532

Dr. I. ThomasDepartment of Energy19901 Germantown RoadGermantown, MD 20874

Ms. T. TsoukatosUniversity of DelawareDepartment of Physics and Astronomy223 Sharp LaboratoryNewark, DE 19716

Dr. K. UnruhUniversity of DelawareDept. of Physics & Astronomy223 Sharp LabNewark, DE 19716

Dr. C. WilliamsCode 6346U.S. Naval Research LaboratoryWashington, DC 20375-5000

Mr. G. ZouganelisNational Center for ScientificResearch "DEMOKRITOS"Institute of Materials Science153 10 Ag. Paraskevi AttikisGREECE