Handbook of advanced magnetic materials. 3, Advanced magnetic materials : fabrication and processing

Preface ......Page 5
Contents ......Page 9
List of Contributors ......Page 15
1.1 Introduction ......Page 17
1.2.1 Magnetic Moment ......Page 19
1.2.2 Exchange ......Page 20
1.2.3 Magnetization and Magnetic Order ......Page 22
1.2.4 Itinerant Magnetism ......Page 24
1.2.5 Magnetic Anisotropy ......Page 26
1.3 Extrinsic Properties ......Page 30
1.3.1 Coherent Rotation ......Page 32
1.3.2 Domains and Domain Walls ......Page 34
1.3.3 Coercivity ......Page 37
1.4.1 Permanent Magnets ......Page 41
1.4.2 Soft Magnets ......Page 43
1.4.3 Recording Media ......Page 44
1.4.5 Tables ......Page 45
1.5 Magnetic Nanostructures ......Page 47
1.5.1 Physical Classification of Magnetic Nanostructures ......Page 48
1.5.2 Intrinsic Properties and Finite-Size Effects ......Page 50
1.5.3 Narrow-Wall and Constricted-Wall Phenomena ......Page 52
1.5.4 Nanomagnetic Localization ......Page 53
1.5.5 Cooperative Effects ......Page 56
1.5.6 Random Anisotropy and Remanence Enhancement ......Page 58
1.5.7 Magnetization Dynamics in Nanostructures ......Page 59
1.5.8 Energy-Barrier Laws ......Page 63
1.6 Conclusions ......Page 65
References ......Page 66
2.1 Introduction ......Page 74
2.2.1 Ultrathin Films ......Page 75
2.2.2 Wires ......Page 77
2.2.3 Dots ......Page 78
2.3.1 Metastable Structures ......Page 80
2.3.2 Dimensionality and Phase Transition ......Page 82
2.3.3 Surface/Interface Electronic Structure ......Page 83
2.3.4 Quantum Size Effects ......Page 85
2.3.5 Domains and Domain Walls ......Page 87
References ......Page 90
3.1 Introduction ......Page 93
3.2.1 Overview of Single-Particle Measurement Techniques ......Page 95
3.2.2 Micro-SQUID Magnetometry ......Page 97
3.3.1 Magnetization Reversal by Uniform Rotation (Stoner-Wohlfarth Model) ......Page 98
3.3.2 Nonuniform Magnetization Reversal ......Page 113
3.4.1 Neel-Brown Model of Thermally Activated Magnetization Reversal ......Page 118
3.4.2 Experimental Methods for the Study of the Neel-Brown Model ......Page 119
3.4.3 Experimental Evidence for the Neel-Brown Model ......Page 122
3.5 Magnetization Reversal by Quantum Tunneling ......Page 128
3.5.1 Quantum Tunneling of Magnetization in Molecular Clusters ......Page 129
3.5.2 Quantum Tunneling of Magnetization in Individual Single-Domain Nanoparticles ......Page 132
3.5.3 Magnetization Measurements of Individual Single-Domain Nanoparticles and Wires at Very Low Temperatures ......Page 134
3.5.4 Quantization of the Magnetization ......Page 136
3.6 Summaries and Conclusions ......Page 138
References ......Page 139
4.1 Introduction ......Page 144
4.2.1 Equation of Motion ......Page 145
4.2.2 Gibbs Free Energy ......Page 146
4.2.3 Langevin Equation ......Page 147
4.2.4 Characteristic Length Scales ......Page 148
4.3.1 Finite Element Discretization ......Page 149
4.3.2 Magnetostatic Field Calculation ......Page 150
4.3.3 Time Integration ......Page 151
4.4.1 Small Particles ......Page 153
4.4.3 Circular Nanodots ......Page 156
4.4.4 Magnetic Nanowires ......Page 158
References ......Page 161
5.1 Introduction ......Page 163
5.2.1 Introduction ......Page 164
5.2.2 Blocking Temperature ......Page 165
5.2.3 a.c. Magnetic Susceptibility Measurement ......Page 166
5.2.4 Zero-Field-Cooled and Field Cooled Magnetization Curves ......Page 171
5.2.5 Magnetic Hysteresis Loops ......Page 174
5.2.6 Numerical Simulation Results ......Page 175
5.3.1 Introduction ......Page 182
5.3.2 Logarithmic Magnetic Relaxation ......Page 183
5.4.1 Introduction ......Page 187
5.4.2 Physics Related to QTM ......Page 188
5.4.3 Observation of QTM in Systems of Nanostructured Materials ......Page 191
References ......Page 193
6.1 Introduction ......Page 198
6.2.1 Energy Product ......Page 200
6.2.2 Fundamental Equations ......Page 202
6.2.3 Nucleation Field ......Page 204
6.2.4 Energy Product ......Page 205
6.2.5 Micromagnetic Localization ......Page 206
6.2.6 Texture ......Page 207
6.2.7 Effective Exchange ......Page 208
6.3.1 FePt-Based Magnets ......Page 212
6.3.2 Rare-Earth Cobalt Magnets ......Page 223
6.3.3 Nd-Fe-B-Based Magnets ......Page 236
6.4 Conclusions ......Page 270
References ......Page 271
7.1 Introduction ......Page 283
7.2 Exchange and Crystal Field Model for (R, R\')-Fe-X System ......Page 285
7.3.1 Magnetic Phase Diagram and Spin Reorientation in (Er1_xTbx)2Fe14B ......Page 287
7.3.2 Magnetostriction and Spin Reorientation in (Eri-xTbx)2Fei4B ......Page 290
7.4.1 Multilayerd Nd2Fe14B/a-Fe Films — — ......Page 294
7.4.2 Nanodispersed Nd2Fe14B/a-Fe Films ......Page 300
7.5 Conclusions ......Page 306
References ......Page 307
8.1 Introduction — ......Page 310
8.2.1 Overview • —— ......Page 311
8.2.2 Scanning Tunneling Microscope Assisted Chemical Vapor Deposition ......Page 312
8.3.1 Overview ......Page 315
8.3.2 Hall Gradiometry ......Page 317
8.3.3 Optimized Hall Measurements for Particle Arrays ......Page 320
8.3.4 Variable Field Magnetic Force Microscopy (MFM) in Nanoparticles ......Page 323
8.4.1 Reversible Rotation of Magnetization ......Page 327
8.4.3 Experimental Results on Magnetization Reversal ......Page 332
8.4.4 Interaction Effects ......Page 333
8.4.5 Comparison to Numerical Simulations ......Page 336
8.5.1 General Considerations ......Page 338
8.5.2 Phenomenological Model ......Page 339
8.5.3 Angular Dependence of Magnetization Reversal ......Page 343
8.5.4 Magnetic Viscosity ......Page 344
References ......Page 347
9.1 Introduction ......Page 355
9.2.1 Magnetic Anisotropies and Magnetic Softness ......Page 357
9.2.2 Random Magnetocrystalline Anisotropy ......Page 361
9.3.1 Grain Size and Magnetic Softness ......Page 367
9.3.2 Intergranular Phase and Magnetic Coupling ......Page 373
9.3.3 Application-Oriented Magnetic Properties ......Page 376
9.4.1 Alloying Elements and Alloy Systems ......Page 380
9.4.2 Alloy Design in Fe-Metal Based Nanocrystalline Alloys ......Page 383
9.4.3 Alloy Design in Fe-Metalloid Based Nanocrystalline Alloys ......Page 384
9.5 Prospects ......Page 386
References ......Page 387
Index ......Page 390