Introduction to the Electronic Properties of Materials David Jiles Ames Laboratory US Department of Energy and Department of Materials Science and Engineering and Department of Electrical and Computer Engineering Iowa State University, USA v% - CHAPMAN & HALL London Glasgow Weinheim New York Tokyo Melbourne Madras
Contents Preface Acknowledgements Glossary of symbols SI units, symbols and dimensions Values of selected physical constants Foreword for the student xiii xiv xv xxi xxii xxiii Part One Fundamentals of Electrons in Materials 1 1 Properties of a material continuum 3 1.1 Relationships between macroscopic properties of materials 3 1.2 Mechanical properties 5 1.3 Electrical properties 7 1.4 Optical properties 11 1.5 Thermal properties 14 1.6 Magnetic properties 17 1.7 Relationships between various bulk properties 20 1.8 Conclusions 20 References 20 Further Reading 21 Exercises 21 2 Properties of atoms in materials 22 2.1 The role of atoms within a material 22 2.2 The harmonic potential model 25 2.3 Specific heat capacity 32 2.4 Conclusions 39 References 39 Further Reading 39 Exercises 39
viii Contents 3 Conduction electrons in materials - classical approach 41 3.1 Electrons as classical particles in materials 41 3.2 Electrical properties and the classical free-electron model 43 3.3 Thermal properties and the classical free-electron model 46 3.4 Optical properties of metals 49 3.5 Conclusions 57 References 58 Further Reading 59 Exercises 59 4 Conduction electrons in materials - quantum corrections 60 4.1 Electronic contribution to specific heat 60 4.2 Wave equation for free electrons 61 4.3 Boundary conditions: the Sommerfeld model 63 4.4 Distribution of electrons among allowed energy levels 69 4.5 Material properties predicted by the quantum freeelectron model 76 4.6 Conclusions 79 References 80 Further Reading 80 Exercises 81 5 Bound electrons and the periodic potential 82 5.1 Models for describing electrons in materials 82 5.2 Solution of the wave equation in a one-dimensional periodic square-well potential 85 5.3 The origin of energy bands in solids: the tight-binding approximation 91 5.4 Energy bands in a solid 94 5.5 Reciprocal or wave vector fe-space 99 5.6 Examples of band structure diagrams 105 5.7 Conclusions 106 References 106 Further Reading 106 Exercises 107 Part Two Properties of Materials 109 6 Electronic properties of metals 111 6.1 Electrical conductivity of metals 111 6.2 Reflectance and absorption 112 6.3 The Fermi surface 114 References 126 Further Reading 127 Exercises 127
Contents 7 Electronic properties of semiconductors 129 7.1 Electron band structures of semiconductors 129 7.2 Intrinsic semiconductors 134 7.3 Extrinsic (or impurity) semiconductors 138 7.4 Optical properties of semiconductors 141 7.5 Photoconductivity 142 7.6 The Hall effect 143 7.7 Effective mass and mobility of charge carriers 145 7.8 Semiconductor junctions 146 References 154 Further Reading 155 Exercises 155 8 Electrical and thermal properties of materials 156 8.1 Macroscopic electrical properties 156 8.2 Quantum mechanical description of conduction electron behaviour 160 8.3 Dielectric properties 163 8.4 Other effects caused by electric fields, magnetic fields and. thermal gradients 166 8.5 Thermal properties of materials 168 8.6 Other thermal properties 172 References 178 Further Reading 179 Exercises 179 9 Optical properties of materials 180 9.1 Optical properties 180 9.2 Interpretation of optical properties in terms of simplified electron band structure 183 9.3 Band structure determination from optical spectra 190 9.4 Photoluminescence and electroluminesence 193 References 196 Further Reading 196 Exercises 196 10 Magnetic properties of materials 198 10.1 Magnetism in materials 198 10.2 Types of magnetic material 201 10.3 Microscopic classification of magnetic materials 203 10.4 Band electron theory of magnetism 207 10.5 The localized electron model of magnetism 215 10.6 Applications of magnetic materials 218 References 218 ix
x Contents Further Reading 219 Exercises 219 Part Three Applications of Electronic Materials 221 11 Microelectronics - semiconductor technology 223 11.1 Use of materials for specific electronic functions 223 11.2 Semiconductor materials 225 11.3 Typical semiconductor devices 226 11.4 Microelectronic semiconductor devices 234 11.5 Future improvements in semiconductors 238 References 241 Further Reading 241 12 Optoelectronics - solid-state optical devices 242 12.1 Electronic materials with optical functions 242 12.2 Materials for optoelectronic devices 245 12.3 Lasers 249 12.4 Fibre optics and telecommunications 255 12.5 Liquid-crystal displays 256 References 257 Further Reading 257 13 Quantum electronics - superconducting materials 259 13.1 Quantum effects in electrical conductivity 259 13.2 Theories of superconductivity 262 13.3 Recent developments in high-temperature superconductors 268 13.4 Applications of superconductors 269 References 278 Further Reading 278 14 Magnetic materials - magnetic recording technology 279 14.1 Magnetic recording of information 279 14.2 Magnetic recording materials 282 14.3 Conventional magnetic recording using particulate media 284 14.4 Magneto-optic recording 290 References 293 Further Reading 293 15 Electronic materials for transducers - sensors and actuators 294 15.1 Transducers 294 15.2 Transducer performance parameters 296 15.3 Transducer materials considerations 299 15.4 Ferroelectric materials 304
Contents 15.5 Ferroelectrics as transducers 307 References 311 Further Reading 312 16 Electronic materials for radiation detection 313 16.1 Radiation sensors 313 16.2 Gas-filled detectors 314 16.3 Semiconductor detectors 315 16.4 Scintillation detectors 321 16.5 Thermoluminescent detectors 322 16.6 Pyroelectric sensors 323 References 323 Further Reading 324 Solutions 325 Subject Index 359 Author Index xi