High Tc Superconductors (eBook)

Front Cover 1
High Tc Superconductors: Electronic Structure 4
Copyright Page 5
Table of Contents 8
Preface 6
PART I: THEORY 12
CHAPTER 1. CHARACTER OF DOPED HOLES AND LOW-ENERGY EXCITATIONS IN HIGH-Tc SUPERCONDUCTORS: ROLES OF THE APEX OXYGEN ATOMS 14
ABSTRACT 14
KEYWORDS 14
INTRODUCTION 14
CLUSTER MODEL 16
SPECTROSCOPIC DETERMINATION OF PARAMETERS 17
CHARACTER OF DOPED HOLES AND LOW-ENERGY EXCITATIONS 20
IMPLICATIONS ON MECHANISMS OF SUPERCONDUCTIVITY 22
CONCLUSION 24
ACKNOWLEDGEMENT 25
REFERENCES 25
CHAPTER 2. ON THE VALIDITY OF THE BAND MODEL FOR HIGH Tc SUPERCONDUCTORS 28
INTRODUCTION 28
ELECTRONIC STRUCTURE AND BONDING 28
ELECTRONIC STRUCTURE AND ANTIFERROMAGNETISM 33
ELECTRONIC STRUCTURE AND XPS/EELS SPECTROSCOPY 37
CONCLUSION AND OUTLOOK 39
ACKNOWLEDGMENTS 40
REFERENCES 40
CHAPTER 3. LOCAL DENSITY APPROXIMATION (LDA) STUDY OF HIGH Tc SUPERCONDUCTORS: FIRST PRINCIPLES CALCULATIONS OF LATTICE STATICS, LATTICE DYNAMICS, AND NORMAL STATE TRANSPORT PROPERTIES OF La2Cu04 42
ABSTRACT 42
KEYWORDS 42
BAND STRUCTURE AND MAGNETISM 44
LATTICE STATICS 44
FIRST PRINCIPLES PHONON CALCULATIONS 44
NORMAL STATE TRANSPORT PROPERTIES 49
CONCLUSIONS 50
REFERENCES 51
CHAPTER 4. CORRELATED ELECTRONS, A NARROW CONDUCTION BAND, AND INTERLAYER PAIRING IN YBCO 54
ABSTRACT 54
ACKNOWLEDGEMENT 59
REFERENCES 59
CHAPTER 5. THERMODYNAMIC AND ELECTRODYNAMIC PROPERTIES IN SYSTEMS WITH LOCAL ELECTRON PAIRING 62
ABSTRACT 62
ACKNOWLEDGEMENT 72
REFERENCES 72
PART II: OPTICAL PROPERTIES 76
CHAPTER 6. THE ENERGY GAP AND TWO-COMPONENT ABSORPTION IN A HIGH Tc SUPERCONDUCTOR 78
ABSTRACT 78
KEYWORDS 78
INTRODUCTION 78
THE ENERGY GAP 80
THE DIELECTRIC CONSTANT 80
TWO COMPONENTS OF THE CONDUCTIVITY 80
FEATURE IN THE CONDUCTIVITY NEAR 50 meV 82
SENSITIVITY OF THE CONDUCTIVITY TO O CONTENT 83
DISTRIBUTION OF SPECTRAL WEIGHT 83
DETERIORATION OF THE CRYSTALS 84
THE FREQUENCY DEPENDENT SCATTERING AND MASS VIEWPOINT 87
CONCLUSION 87
ACKNOWLEDGEMENTS 87
REFERENCES 87
CHAPTER 7. VIBRATIONAL MODES IN THE Cu02 PLANES OF YBa2Cu307_5 90
ABSTRACT 90
KEYWORDS 90
INTRODUCTION 90
EXPERIMENTAL RESULTS 91
DISCUSSION 93
CONCLUSION 96
ACKNOWLEDGEMENT 96
REFERENCES 96
CHAPTER 8. ABSORPTION AND PHOTOINDUCED ABSORPTION STUDIES OF La2Cu04 and YBa2Cu306+x: ROLE OF DEFECT STATES 98
ABSTRACT 98
KEYWORDS 98
INTRODUCTION 99
EXPERIMENTAL 100
EXPERIMENTAL RESULTS 101
DISCUSSION 102
ACKNOWLEDGEMENT 103
REFERENCES 104
CHAPTER 9. PHOTOINDUCED OPTICAL EXCITATIONS IN THE YBa2CU307.y HIGH TC SUPERCONDUCTING SYSTEM 106
ABSTRACT 106
INTRODUCTION 106
EXPERIMENTAL 107
PHOTOINDUCED ABSORPTION 107
ELECTRONIC SPECTRA 108
PHONON SPECTRUM 110
ACKNOWLEDGEMENTS 111
REFERENCES 111
CHAPTER 10. ANOMALOUS HEATING OF OXYGEN VIBRATIONS IN RAMAN SPECTRA OF YBa2Cu307-8 114
ABSTRACT 114
KEYWORDS 114
INTRODUCTION 114
MEASUREMENTS 115
RESULTS 116
DISCUSSION 117
REFERENCES 118
PART III: MAGNETIC INTERACTIONS 120
CHAPTER 11. NUCLEAR MAGNETIC RESONANCE IN HIGH TEMPERATURE SUPERCONDUCTOR 122
ABSTRACT 122
KEYWORDS 122
INTRODUCTION 122
RESULTS 124
17o NMR SPECTRA 128
NUCLEAR RELAXATION BEHAVIOR OF 17o 129
CONCLUSION 131
REFERENCES 131
CHAPTER 12. NEUTRON SCATTERING STUDIES OF MAGNETIC EXCITATIONS IN La2.xSrxCu04 134
ABSTRACT 134
INTRODUCTION 134
PHASE DIAGRAM 135
INSTANTANEUS AND QUASIELASTIC SPIN CORRELATIONS 138
CONCLUSIONS 146
ACKNOWLEDGEMENTS 148
REFERENCES 148
CHAPTER 13. Bi2Sr2Y1-xCaxCu2O8+8: THE MAGNETIC PARTNER OF Bi2Sr2CaCu2O8 A NMR AND µSR STUDY. 152
ABSTRACT 152
REFERENCES 157
CHAPTER 14. LOW FIELD MICROWAVE ABSORPTION IN CERAMIC YBa2Cu3O7-8 160
ABSTRACT 160
REFERENCES 164
PART IV: MATERIALS 166
CHAPTER 15. OZONE ANNEALING OF YBCO SUPERCONDUCTORS: TOWARD THE MAXIMUM OF DIAMAGNETIC Tc AND MINIMUM OF ATC 168
ABSTRACT 168
KEYWORDS 168
INTRODUCTION 168
FABRICATION PROCESS AND MEASUREMENT APPARATUS 169
SAMPLES CHARACTERIZATION 171
CONCLUSION 175
REFERENCES 175
PART V: PHOTOEMISSION 178
CHAPTER 16. PHOTOEMISSION ON HIGH Tc SUPERCONDUCTORS 180
ABSTRACT 180
INTRODUCTION 180
VALENCE BAND SPECTRA 181
CORE LEVEL SPECTRA 184
CONCLUSION 189
ACKNOWLEDGEMENTS 189
REFERENCES 189
CHAPTER 17. PHOTOEMISSION SPECTROSCOPY OF Bi2CaSr2Cu2O8+8 IN THE NORMAL AND SUPERCONDUCTING STATE 192
ABSTRACT 192
KEYWORDS 192
ACKNOWLEDGEMENTS 195
REFERENCES 195
CHAPTER 18. ELECTRONIC STRUCTURE OF YBa2Cu3O7-8 AND Bi2Sr2CaCu2O8+8 BY X-RAY PHOTOEMISSION AND AUGER SPECTROSCOPIES 196
ABSTRACT 196
KEYWORDS 196
INTRODUCTION 196
EXPERIMENTAL 197
RESULTS 198
DISCUSSION 203
CONCLUSIONS 208
REFERENCES 209
CHAPTER 19. INTERFACE FORMATION BETWEEN METALS AND HIGH-TC SUPERCONDUCTORS 212
ABSTRACT 212
KEYWORDS 212
INTRODUCTION 212
EXPERIMENTAL 214
INTERFACES WITH YBa2Cu3O7-8 214
INTERFACES WITH Bi5Sr3Ca2Cu4Oy 219
SUMMARY 224
REFERENCES 224
CHAPTER 20. RESONANT PHOTOEMISSION NEAR O Is THRESHOLD IN YBa2Cu2.7FeO.3O6.9 226
ABSTRACT 226
CONCLUSION 233
ACKNOWLEDGEMENT 233
REFERENCES 233
CHAPTER 21. Electron Spectroscopy Studies of High Temperature Superconductors: Y1-xPrxBa2Cu3O7_8 236
ABSTRACT 236
KEYWORDS 236
INTRODUCTION 236
EXPERIMENTAL DETAILS 237
PHOTOEMISSION SPECTRA 238
BIS SPECTRA 240
Pr 4f SPECTRUM 241
DISCUSSION 244
ACKNOWLEDGEMENTS 245
REFERENCES 246
CHAPTER 22. ELECTRONIC STRUCTURE STUDIES OF Bi-Sr-Ca-Cu-O SINGLE CRYSTAL SUPERCONDUCTOR 248
ABSTRACT 248
CONCLUSION 252
REFERENCES 253
PART VI: X-RAY SPECTROSCOPY 254
CHAPTER 23. OXYGEN-DEPENDENT ELECTRONIC STRUCTURE IN POWDER AND SINGLE CRYSTAL OF YBa2Cu3O7-8 OBSERVED IN-SITU BY X-RAY ABSORPTION SPECTROSCOPY 256
ABSTRACT 256
KEYWORDS 256
THE COPPER K-EDGE OF SOME SIGNIFCANT STANDARDS COMPOUNDS 258
IN-SITU UPTAKE AND REMOVAL OF OXYGEN UPON ANNEALING 259
GENERAL DISCUSSION. 264
ACKNOWLEDGEMENTS: 266
REFERENCES 266
CHAPTER 24. ON THE VARIATION OF THE Cu K-EDGE XANES OF YBa2Cu3O7_x WITH OXYGEN CONCENTRATION 270
ABSTRACT 270
KEYWORDS 270
INTRODUCTION 270
RESULTS 273
REFERENCES 280
CHAPTER 25. ON THE TEMPERATURE DEPENDENCE OF THE Cu-0 STRUCTURE IN EuBa2Cu3O7-8 282
ABSTRACT 282
KEYWORDS 282
INTRODUCTION 282
EXPERIMENT 283
RESULTS AND DISCUSSION 286
REFERENCES 291
ACKNOWLEDGEMENTS 291
CHAPTER 26. CORRELATION BETWEEN Tc OF CUPRATE SUPERCONDUCTORS AND THE ENERGY SPLITTING BETWEEN IN-PLANE AND OUT-OF-PLANE POLARIZED Cu 2p-> 3d TRANSITION
ABSTRACT 292
KEYWORDS 292
INTRODUCTION 293
EXPERIMENTAL 294
RESULTS 295
ACKNOWLEDGEMENTS 300
REFERENCES 300
CHAPTER 27. ELECTRONIC STRUCTURE STUDIES OF HIGH-TC SUPERCONDUCTORS BY VALENCE AND CORE ELECTRON EXCITATIONS 304
ABSTRACT 304
KEYWORDS 304
INTRODUCTION 304
EXPERIMENTAL 306
RESULTS AND DISCUSSION 306
ACKNOWLEDGEMENTS 320
REFERENCES 320
CHAPTER 28. JOINT ANALYSIS OF Cu L3 XAS AND XPS SPECTRA OF HIGH Tc SUPERCONDUCTORS FOR DETERMINATION OF THE STATES INDUCED BY DOPING 324
ABSTRACT 324
INTRODUCTION 324
EXPERIMENTAL 326
RESULTS AND DISCUSSION 326
CONCLUSIONS 333
REFERENCES 334
CHAPTER 29. SOFT X-RAY EMISSION SPECTRA OF HIGH Tc SUPERCONDUCTORS 336
ABSTRACT 336
KEYWORDS 336
INTRODUCTION 336
EXPERIMENTAL 338
RESULTS AND DISCUSSION 339
REFERENCES 347