Science And Technology Of Nanostructured Magnetic Materials (nato Science Series B: (closed))

Proceedings of a NATO ASI held in Aghia Pelaghia, Crete, Greece, June 24--July 6, 1990 Of Progress Has Been Made In The Development Of In The Last Twenty Years A Great Amount New Magnetic Materials. Permanent Magnets Have Progressed From The Alnico's (with (bh)m-8 Mgoe) To The Strong Rare-earth Magnets Of Smco «bh)m-20 Mgoe), Sm2(co,fe,cu,zrh7 S «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 Fe0 And Cro For Storage Media And 2 3 Z 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 Seen In Bulk Materials. Thin Films, Surfaces And Interfaces -- Electronic Structure And Magnetism Of Metal Surfaces, Overlayers And Interfaces -- Growth And Magnetic Properties Of Metastable Structures -- Spin-resolved Photoemission -- Correlation Of Crystalline And Electronic Structure In Epitaxial Fcc-cobalt Monolayers On Cu(100) -- Hybrid Ferromagnetic/semiconductor Structures -- Mössbauer Studies Of Ultrathin Magnetic Films Of Fe/ag(100) -- Spin-dependence Of Absorbed And Reflected Current On Fe(110) -- Mbe Growth Of Metal/semiconductor Interfaces -- Surface And Interface Magnetism -- Ferromagnetic Resonance Studies Of Bcc Epitaxial Ultrathin Fe(001)/cu(001) Bilayers And Fe(001)/cu(001)/fe(001) Trilayers -- Laser Ablation Deposition Of Metallic Thin Films -- Exchange Coupled Films For Magneto-optic Applications -- Temperature Dependence Of Micromagnetic Domain Structure In Cobalt Films -- Hyperfine Interaction Techniques Applied To The Study Of Surfaces And Interfaces -- Surface Magnetostriction --^ Multilayers -- Magnetic Rare Earth Artificial Metallic Superlattices -- X-ray Characterization Of Magnetic Multilayers And Superlattices -- The Characterization Of Interface Roughness And Other Defects In Multilayers By X-ray Scattering -- Magnetism Of Nanostructured Rare Earth Multilayers -- Fmr Studies Of Metallic Magnetic Thin Films In Layered Structures -- Compositionally Modulated Magnetic Multilayers: Temperature- And Modulation-dependent Properties -- Structural And Magnetic Properties Of Epitaxial Co/pd Superlattices -- First-principles Calculation Of The Magnetocrystalline Anisotropy Energy Of Conpdm Multilayers -- Structural And Magnetic Studies In Co-pt Multilayers -- Magnetic Properties Of Hexagonal Fe/ru Superlattices With Short Periodicity -- Magnetic Studies Of Fe-si Compositionally Modulated Thin Films -- Mössbauer Spectroscopy Of The Fe/ni Interface -- Analysis Of Amorphous Dysprosium-transition Metal Nanoscale Magnetic Multilayers --^ Transport Properties Of Thin Metallic Films And Multilayers -- Domain Walls, Magnetic Domains And Techniques For Their Observation -- Micromagnetics Of Longitudinal Recording Media -- Mo-recording: The Switching Process And Its Relation To The Magnetic Properties Of Thin Films -- Micromagnetic Computations Of Magnetization Configurations -- Domain Walls And Wall Structure -- Domain Wall Multiplication In Amorphous Ferromagnetic Alloys -- Electron Microscope Methods For Imaging Internal Magnetic Fields At High Spatial Resolution -- Scanning Tunneling Microscopy And Force Microscopy Applied To Magnetic Materials -- Special Session On Spin-polarized Vacuum Tunneling -- Magnetic Imaging Via Scanning Electron Microscopy With Polarization Analysis -- Atomic Scale Probe Into High-tc Superconductors Using Scanning Tunnelling Microscopy -- Magnetic Anisotropy And Random Magnets -- Magnetic Anisotropy -- Random Anisotropy In Magnetic Materials --^ Perpendicular And In-plane Anisotropy In Amorphous Tb-fe -- Magnetostriction In Amorphous Ferromagnets -- Anderson Localization In 3-dimensional Amorphous Alloys: Evolution With The Content Of Magnetic Ions -- On The Law Of Approach To Saturation In The Series Of Amorphous Alloys A-dyxd1?xni -- Magnetoresistance Of Amorphous U1?xsbx Films -- Absence Of Temperature-driven First-order Phase Transitions In Systems With Random Bonds -- Magnetic Semiconductors And Intermetallic Compounds -- Magnetic Behavior Of Diluted Magnetic Semiconductors -- Intermetallic Compounds And Crystal Field Interactions -- Crystal-field And Exchange Interactions In Hard Magnetic Materials -- First Order Magnetization Processes -- Structure And Properties Of Novel Ternary Fe-rich Rare-earth Carbides -- Fine Particles -- Granular Solids -- Ultrafine Magnetic Particles -- Magnetic Nanometer Systems And Mössbauer Spectroscopy -- Some Topics In Fine Particle Magnetism --^ Mössbauer Studies Of Fine Fe-based Particles -- Mössbauer Studies Of Fine Particles Of Fe-cr-b -- Chemical Preparation Of Amorphous Fe-cr-b Particles -- Composition And Structure Of Fe-ni-b Alloy Particles Prepared By Chemical Reduction With Nabh4 -- Quantum Effects In Ultrafine Nd-fe-b Particles -- Magnetization Reversal In Clusters Of Magnetic Particles -- Electric And Magnetic Properties Of Small Systems -- Existence Of Frequency Cut-off In The Spin Wave Spectrum Of Small Magnetic Particles -- Magnetic Hysteresis And Permanent Magnets -- Mechanically Alloyed Permanent Magnets -- Melt-spun Magnets -- Solid Ndfeb Magnets Made By Gas Atomization And Extrusion -- The Role Of Microstructure In Permanent Magnets -- Lorentz Microscopy Studies In Permanent Magnets -- Coercivity In Hard Magnetic Materials -- Micromagnetism And Magnetization Processes In Modern Magnetic Materials -- Micromagnetic Approach To Magnetic Hysteresis -- Magnetic Hysteresis In Disordered Magnets --^ Coercivity Of Nanostructured Materials -- Magnetic Hysteresis Of Copt Films -- Technology And Applications Of Permanent Magnets -- Author Index. Edited By George C. Hadjipanayis, Gary A. Prinz. Front Matter....Pages i-xi Electronic Structure and Magnetism of Metal Surfaces, Overlayers and Interfaces....Pages 1-13 Growth and Magnetic Properties of Metastable Structures....Pages 15-24 Spin-Resolved Photoemission....Pages 25-35 Correlation of Crystalline and Electronic Structure in Epitaxial FCC-Cobalt Monolayers on Cu(100)....Pages 37-40 Hybrid Ferromagnetic/Semiconductor Structures....Pages 41-54 Mossbauer Studies of Ultrathin Magnetic Films of Fe/Ag(100)....Pages 55-60 Spin-Dependence of Absorbed and Reflected Current on FE(110)....Pages 61-65 MBE Growth of Metal/Semiconductor Interfaces....Pages 67-70 Surface and Interface Magnetism....Pages 71-76 Ferromagnetic Resonance Studies of BCC Epitaxial Ultrathin Fe(001)/Cu(001) Bilayers and Fe(001)/Cu(001)/Fe(001) Trilayers....Pages 77-80 Laser Ablation Deposition of Metallic Thin Films....Pages 81-89 Exchange Coupled Films for Magneto-Optic Applications....Pages 91-97 Temperature Dependence of Micromagnetic Domain Structure in Cobalt Films....Pages 99-102 Hyperfine Interaction Techniques Applied to the Study of Surfaces and Interfaces....Pages 103-108 Surface Magnetostriction....Pages 109-116 Magnetic Rare Earth Artificial Metallic Superlattices....Pages 117-136 X-Ray Characterization of Magnetic Multilayers and Superlattices....Pages 137-144 The Characterization of Interface Roughness and Other Defects in Multilayers by X-Ray Scattering....Pages 145-149 Magnetism of Nanostructured Rare-Earth Multilayers....Pages 151-170 FMR Studies of Metallic Magnetic Thin Films in Layered Structures....Pages 171-176 Compositionally Modulated Magnetic Multilayers: Temperature- and Modulation-Dependent Properties....Pages 177-180 Structural and Magnetic Properties of Epitaxial Co/Pd Superlattices....Pages 181-184 First-Principles Calculation of the Magnetocrystalline Anisotropy Energy of Co n Pd m Multilayers....Pages 185-190 Structural and Magnetic Studies in Co-Pt Multilayers....Pages 191-194 Magnetic Properties of Hexagonal Fe/Ru Superlattices with Short Periodicity....Pages 195-200 Magnetic Studies of Fe-Si Compositionally Modulated Thin Films....Pages 201-207 Mössbauer Spectroscopy of the Fe/Ni Interface....Pages 209-214 Analysis of Amorphous Dysprosium-Transition Metal Nanoscale Magnetic Multilayers....Pages 215-219 Transport Properties of Thin Metallic Films and Multilayers....Pages 221-237 Micromagnetics of Longitudinal Recording Media....Pages 239-247 MO-Recording: The Switching Process and its Relation to the Magnetic Properties of Thin Films....Pages 249-254 Micromagnetic Computations of Magnetization Configurations....Pages 255-268 Domain Walls and Wall Structure....Pages 269-274 Domain Wall Multiplication in Amorphous Ferromagnetic Alloys....Pages 275-278 Electron Microscope Methods for Imaging Internal Magnetic Fields at High Spatial Resolution....Pages 279-300 Scanning Tunneling Microscopy and Force Microscopy Applied to Magnetic Materials....Pages 301-329 Special Session on Spin-Polarized Vacuum Tunneling....Pages 331-334 Magnetic Imaging via Scanning Electron Microscopy with Polarization Analysis....Pages 335-338 Atomic Scale Probe into High-Tc Superconductors Using Scanning Tunnelling Microscopy....Pages 339-347 Magnetic Anisotropy....Pages 349-365 Random Anisotropy in Magnetic Materials....Pages 367-376 Perpendicular and in-Plane Anisotropy in Amorphous Tb-Fe....Pages 377-385 Magnetostriction in Amorphous Ferromagnets....Pages 387-392 Anderson Localization in 3-Dimensional Amorphous Alloys: Evolution with the Content of Magnetic Ions....Pages 393-397 On the Law of Approach to Saturation in the Series of Amorphous Alloys a-Dy x Gd 1−x Ni....Pages 399-404 Magnetoresistance of Amorphous U 1−x Sb x Films....Pages 405-410 Absence of Temperature-Driven First-Order Phase Transitions in Systems with Random Bonds....Pages 411-417 Magnetic Behavior of Diluted Magnetic Semiconductors....Pages 419-438 Intermetallic Compounds and Crystal Field Interactions....Pages 439-458 Crystal-Field and Exchange Interactions in Hard Magnetic Materials....Pages 459-464 First Order Magnetization Processes....Pages 465-470 Structure and Properties of Novel Ternary Fe-Rich Rare-Earth Carbides....Pages 471-476 Granular Solids....Pages 477-496 Ultrafine Magnetic Particles....Pages 497-510 Magnetic Nanometer Systems and Mössbauer Spectroscopy....Pages 511-532 Some Topics in Fine Particle Magnetism....Pages 533-544 Mössbauer Studies of Fine Fe-Based Particles....Pages 545-550 Mössbauer Studies of Fine Particles of Fe-Cr-B....Pages 551-557 Chemical Preparation of Amorphous Fe-Cr-B Particles....Pages 559-562 Composition and Structure of Fe-Ni-B Alloy Particles Prepared by Chemical Reduction with NaBH 4 ....Pages 563-566 Quantum Effects in Ultrafine Nd-Fe-B Particles....Pages 567-572 Magnetization Reversal in Clusters of Magnetic Particles....Pages 573-576 Electric and Magnetic Properties of Small Systems....Pages 577-580 Existence of a Frequency Cut-Off in the Spin Wave Spectrum of Small Magnetic Particles....Pages 581-581 Mechanically Alloyed Permanent Magnets....Pages 583-590 Melt-Spun Magnets....Pages 591-597 Solid NdFeB Magnets Made by Gas Atomization and Extrusion....Pages 599-606 The Role of Microstructure in Permanent Magnets....Pages 607-626 Lorentz Microscopy Studies in Permanent Magnets....Pages 627-633 Coercivity in Hard Magnetic Materials....Pages 635-656 Micromagnetism and Magnetization Processes in Modern Magnetic Materials....Pages 657-675 Micromagnetic Approach to Magnetic Hysteresis....Pages 677-682 Magnetic Hysteresis in Disordered Magnets....Pages 683-694 Coercivity of Nanostructured Materials....Pages 695-699 Magnetic Hysteresis of CoPt Films....Pages 701-706 Technology and Applications of Permanent Magnets....Pages 707-716 Back Matter....Pages 717-720 Of progress has been made in the development of In the last twenty years a great amount new magnetic materials. Permanent magnets have progressed from the AlNiCo's (with (BH)m-8 MGOe) to the strong rare-earth magnets of SmCo {laquo}BH)m-20 MGOe), Sm2(Co, Fe, Cu, Zrh7 s {laquo}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 Fe0 and CrO for storage media and 2 3 z 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 seen in bulk materials