Ultrathin Magnetic Structures IV (eBook)

Bret Heinrich: Professor Physics Department, Simon Fraser University, Director Surface Physics Laboratory , SFU; Fellow of American Physical Society; Associate member of Canadian Institute for Advanced Research CIAR); member of Canadian European Research Initiative on Nanostructures (CERION II); a fellow of Alexander von Humboldt Foundation, member of Advisory Committee, Annual Conference on Magnetism and Magnetic Materials (MMM), American Institute of Physics; member of International Advisory Committee, International Colloquium on Thin Films and Surfaces (ICMFS). Anthony Bland: Professor at the Cavendish Laboratory, Cambridge University, Fellow of the Institute of Physics (UK), and Fellow of Selwyn College has directed the Thin Film Magnetism group at the Cavendish Laboratory since 1989. He frequently serves as an advisory committee member (Rutherford Laboratory, UK and various international conferences) and was awarded the Wohlfarth prize by the Institute of Physics and the Institute of Electrical Engineers in 1999.

Preface 5
Contents 7
Contributors 11
Acronyms 13
1 Introduction 15
2 Magnetoelectronics 18
2.1 Background 18
2.2 Commercialized Applications 20
2.3 Developing Technology 20
2.4 Future Opportunities 27
2.5 Conclusion 30
References 30
3 Electrical Spin Injection into Semiconductors 32
3.1 Introduction 32
3.2 Device Concepts 33
3.3 Spin Injection from Semimagnetic Semiconductors 39
3.4 Spin Injection across an Air-Exposed Semiconductor Interface 42
3.5 Role of Interface Structure in Spin Injection 45
3.6 Ferromagnetic Metals as Spin Injecting Contacts 51
3.7 Characteristics of the Fe/AlGaAs(001) Interface 62
3.8 Summary 66
References 68
4 Optical Studies of Electron Spin Transmission 72
4.1 Introduction to Spin Electronics 72
4.2 Spin Filtering Experiments in Ferromagnet/ Semiconductor Hybrid Structures 83
4.3 Spin Filtering in Ferromagnet/ Semiconductor Schottky Diodes 88
4.4 Spin Filtering in Ferromagnet/ Barrier Layer/ Semiconductor Junctions 93
4.5 Ballistic Spin Transport in Spin Valve Structures 101
4.6 Summary 109
References 110
5 Introduction to Micromagnetics 114
5.1 First Spin Around the Track 114
5.2 One Atom of Iron 115
5.3 Non-uniform Magnetization 140
References 161
6 Spin Valve Giant Magnetoresistive Sensor Materials for Hard Disk Drives 162
6.1 Introduction 162
6.2 The GMR Effect 166
6.3 A Simple But Powerful Model 167
6.4 Biasing and Device Physics 171
6.5 Antiferromagnets in Spin Valves 172
6.6 Menagerie of Spin Valve Structures 174
6.7 Future Directions 180
Appendix: Semiclassical Theory of GMR 183
References 187
7 Magnetic Switching in High-Density MRAM 189
7.1 Random Access Memories (RAMs) 189
7.2 Magnetoresistive Random Access Memory (MRAM) 191
7.3 MRAM Cell Scaling 201
7.4 Coherent Rotation of Single-Domain Elements 202
7.5 Switching of Submicron MRAM Devices 208
7.6 Micromagnetic Properties of Submicron MRAM Devices 214
7.7 Issues Related to Magnetic Switching in Future High- Density MRAM 222
References 227
8 Giant Magneto-resistive Random-Access Memories Based on Current- in- Plane Devices 231
8.1 Introduction 231
8.2 Magnetic Pseudo-Spin-Valve Device Switching Characteristics, Modeling, and Distributions 234
8.3 The 1R0T GMRAM Architecture 255
8.4 Magnetic Spin-Valve Devices for GMRAMs and GMRAM Latch Architectures 258
8.5 Nonvolatile Memory Comparisons and Potential Applications 260
8.6 Conclusions 262
References 263
Subject Index 265