Page 10 - Electrical Properties of Materials

Contents ix

11 Magnetic materials
11.1 Introduction 259
11.2 Macroscopic approach 260
11.3 Microscopic theory (phenomenological) 260
11.4 Domains and the hysteresis curve 264
11.5 Soft magnetic materials 268
11.6 Hard magnetic materials (permanent magnets) 270
11.7 Microscopic theory (quantum-mechanical) 273
11.7.1 The Stern–Gerlach experiment 278
11.7.2 Paramagnetism 278
11.7.3 Paramagnetic solids 280
11.7.4 Antiferromagnetism 281
11.7.5 Ferromagnetism 281
11.7.6 Ferrimagnetism 282
11.7.7 Garnets 282
11.7.8 Helimagnetism 282
11.8 Magnetic resonance 282
11.8.1 Paramagnetic resonance 282
11.8.2 Electron spin resonance 283
11.8.3 Ferromagnetic, antiferromagnetic, and ferrimagnetic resonance 283
11.8.4 Nuclear magnetic resonance 283
11.8.5 Cyclotron resonance 284
11.9 The quantum Hall effect 284
11.10 Magnetoresistance 286
11.11 Spintronics 287
11.11.1 Spin current 287
11.11.2 Spin tunnelling 289
11.11.3 Spin waves and magnons 290
11.11.4 Spin Hall effect and its inverse 290
11.11.5 Spin and light 290
11.11.6 Spin transfer torque 291
11.12 Some applications 291
11.12.1 Isolators 291
11.12.2 Sensors 292
11.12.3 Magnetic read-heads 292
11.12.4 Electric motors 293
Exercises 293

12 Lasers
12.1 Equilibrium 295
12.2 Two-state systems 295
12.3 Lineshape function 299
12.4 Absorption and amplification 301
12.5 Resonators and conditions of oscillation 301
12.6 Some practical laser systems 302
12.6.1 Solid state lasers 303
12.6.2 The gaseous discharge laser 304
12.6.3 Dye lasers 305
12.6.4 Gas-dynamic lasers 306
12.6.5 Excimer lasers 307
12.6.6 Chemical lasers 307