Magnetic Materials and Their Applications (eBook)

Front Cover 1
Magnetic Materials and their Applications 4
Copyright Page 5
Table of Contents 8
Preface 6
Chapter 1. INTRODUCTION 16
REFERENCES 17
Chapter 2. REVIEW OF MAGNETIC EFFECTS 19
2.1 Preliminary Remarks 19
2.2 The Most Important Effects 19
Chapter 3. MAGNETIC PARAMETERS OF MATERIALS 31
3.1 Types of Magnetic Materials 31
3.2 The Principal Concepts and Definitions 34
Chapter 4. THE MAGNETISING PROCESS AND THE BASIS OF THE HYSTERESIS LOOP 116
4.1 The Origin of Magnetism 116
4.2 Magnetic Domains 120
4.3 The Magnetising Process 125
4.4 Magnetising Processes and the Hysteresis Loop for Polycrystalline Materials 127
4.5 Magnetising Processes in Single Crystals 133
4.6 Micromagnetics 139
4.7 Magnetisation of Thin Films 141
4.8 The Rayleigh Loop 143
4.9 The Steinmetz Law 145
4.10 The Various Segments of the Hysteresis Loop and Their Practical Applications 147
Chapter 5 THE VARIOUS SHAPES OF HYSTERESIS LOOPS AND THEIR PHYSICAL CAUSES 151
5.1 The Normal Hysteresis Loop 151
5.2 The Rectangular Loop 152
5.3 Perminvar Loops 160
5.4 Isoperm Loops 170
Chapter 6 FACTORS INFLUENCING MAGNETIC BEHAVIOUR 177
6.1 The Influence of Impurities and Low-level Additives 177
6.2 Effect of the Manufacturing Process 183
6.3 Effects due to Mechanical Working 199
6.4 Ambient Effects 206
Chapter 7 MECHANICAL PROPERTIES 214
7.1 Crystal Structure 214
7.2 Density 221
7.3 Melting Point 223
7.4 Special Mechanical Properties 223
Chapter 8 ELECTRICAL PROPERTIES OF MAGNETIC MATERIALS 227
8.1 Specific Electrical Resistance 227
8.2 Dielectric Constant and Loss Angle 244
Chapter 9 PERMANENT-MAGNET MATERIALS 253
9.1 Role of the Permanent Magnet 253
9.2 Descriptive Characteristics of Permanent-magnet Materials 253
9.3 The Optimum Working Point 255
9.4 Dimensioning a Permanent Magnet 256
9.5 Fulness Factor 259
9.6 Stabilising 259
9.7 Influence of Temperature 263
9.8 Residual Effect and Ageing 266
9.9 The Working Line 269
9.10 The Fundamental Types of Permanent-magnet Materials 270
9.11 Varieties of Permanent-magnet Materials Available from Industry 310
9.12 Applications of Permanent Magnets 310
Chapter 10 MAGNETIC MATERIALS IN HEAVY-CURRENT ENGINEERING 320
10.1 Requirements for Laminated Materials 320
10.2 Unalloyed Iron 322
10.3 Fe-Si Alloys 327
10.4 Fe-Al Alloys 354
10.5 Fe-Si-Al Alloys 360
10.6 Fe-Co Alloys 363
10.7 Ferrite Cores for Power Transformers 364
Chapter 11 MATERIALS FOR TRANSDUCTOR CORES 372
11.1 Principles and Properties of a Transductor 372
11.2 Transductor Applications 376
11.3 Requirements for Core Material 377
11.4 Miscellaneous Materials 378
11.5 Effect of Core Construction 385
Chapter 12 MAGNETIC MATERIALS FOR RELAYS 406
12.1 Uses and Properties of the Electromagnetic Relay 406
12.2 Material Requirements for Core and Yoke 409
12.3 Magnetic Ageing 410
12.4 Classification of Magnetically Soft Materials for Relays 413
12.5 Unalloyed Iron 415
12.6 Fe-Si Alloys 418
12.7 Fe-Ni Alloys 419
12.8 Fe-Co Alloys 420
12.9 Ferrites 420
Chapter 13 CORE MATERIALS FOR INDUCTANCE COILS AND TRANSFORMERS 423
13.1 Magnetic Materials in Communications Technology 423
13.2 Inductively Loaded Conductors 423
13.3 Specified Requirements for Inductance Coils and Transformer Cores 425
13.4 Solid Metal and Alloy Core Materials 426
13.5 Dust Cores 457
13.6 Ferrites 483
Chapter 14 MAGNETIC MATERIALS FOR THE MICROWAVE REGION 550
14.1 Electromagnetic Waves in Waveguides 550
14.2 The Reciprocity Principle 552
14.3 Electrical Properties of Ferrites at Super-high Frequencies 554
14.4 Magnetic Properties of Ferrites in a Microwave Field 556
14.5 Materials 583
14.6 Microwave Components using Ferrite 598
Chapter 15 MAGNETIC MATERIALS FOR INFORMATION STORAGE 607
15.1 Types of Magnetic Store 607
15.2 Historical 609
15.3 Tape Recorders 610
15.4 Drum Stores 617
15.5 Magnetic Disc Stores 620
15.6 Toroidal Core Stores 622
15.7 Ferrite Storage Plates 649
15.8 Thin-film Stores 650
15.9 Cylindrical Thin-film Storage Elements 660
15.10 The Waffle-iron Memory Store 662
15.11 Transfluxors 663
15.12 The Twistor 667
15.13 The Magnetostrictive Delay Line 671
15.14 The Orthoferrite Memory 672
Chapter 16 MATERIALS FOR MAGNETOMECHANICAL RESONATORS 682
16.1 Applications 682
16.2 Requirements Specified for the Material 683
16.3 The Magnetomechanical Coupling Factor 684
16.4 Forms of Mechanical Oscillator 685
16.5 Example of a Magnetostrictive Filter 688
16.6 Materials 688
Chapter 17 MATERIALS FOR MAGNETIC SHIELDING 700
17.1 Stray-field Effects 700
17.2 Operation of a Shield 701
17.3 The Shielding Factor 702
17.4 Magnetic-shield Materials 704
Chapter 18 MATERIALS FOR TEMPERATURE COMPENSATION 707
18.1 Problem and Principles 707
18.2 Materials 708
Chapter 19 TABLES 713
19.1 Tables of Materials 713
19.2 Trade Names and Producers of Magnetic Materials 759
INDEX 782