High Temperature Superconductors

High Temperature Superconductors......Page 2
Contents......Page 8
Preface......Page 14
List of Contributors......Page 18
1.1.1 The Superconducting Phenomenon......Page 22
1.1.2 Superconductivity and Quantum Mechanics......Page 24
1.1.2.1 Wave-Particle Duality......Page 25
1.1.2.2 Fermion and Boson......Page 26
1.1.2.3 Zero Resistance......Page 27
1.1.2.4 Origin of Formation of a Cooper Pair......Page 28
1.1.2.5 Josephson Effect......Page 29
1.1.3.1 Superconductor in Magnetic Field......Page 30
1.1.3.2 London Equations......Page 31
1.1.3.3 Ginzburg-Landau Theory......Page 33
1.1.3.4 Type I and Type II Superconductors......Page 34
1.1.3.5 Mixed State......Page 35
1.2.1.1 Elements......Page 38
1.2.1.2 Alloys......Page 39
1.2.2.1 A15 Type Compound......Page 40
1.2.2.2 Nitride and Chevrel Compound......Page 42
1.2.2.3 MgB2......Page 43
1.2.3 Organic Superconductors......Page 44
1.3.1 Early Oxide Superconductors......Page 46
1.3.2.1 Crystal Structure......Page 47
1.3.2.2 Electronic Structure......Page 49
1.3.2.3 Anisotropy and Vortex Lattice Melting......Page 51
1.3.2.4 Vortex Glass and Bose Glass......Page 53
1.3.3 Other High-Tc Oxide Superconductors......Page 54
1.4.1.1 Current–Voltage Characteristic......Page 55
1.4.1.2 Depairing Current Density......Page 56
1.4.2.1 Elementary Pinning Force......Page 57
1.4.2.2 Elasticity of Vortex Lattice......Page 58
1.4.2.3 Global Pinning Force......Page 59
1.4.2.4 Scaling Rule......Page 60
1.4.3.1 Critical State Model......Page 61
1.4.3.2 Vortex Creep and TAFF......Page 62
1.4.3.3 Thermal Fluctuation......Page 64
1.4.4 Grain Boundary Problem......Page 65
References......Page 67
2.1 Introduction......Page 70
2.2 Experimental Details......Page 73
2.2.2 Swept Field Method (Figure 2.2b)......Page 74
2.3.1 Field Dependence of Current Density......Page 75
2.3.2 E–J Characteristics......Page 76
2.3.3 Magnetic Relaxation......Page 79
2.3.3.1 Results of Creep Experiments......Page 80
2.3.3.2 ‘Maley Analysis\'......Page 81
2.3.4 The Power Law Index n......Page 83
2.4 Conclusions......Page 84
References......Page 85
3.1 Introduction......Page 88
3.2 Raman Measurement Methods......Page 89
3.3.1 REBCO Superconductors......Page 91
3.3.1.1 REBCO Oxygen Stoichiometry and Texture......Page 92
3.3.1.2 Disorder in the REBCO Lattice......Page 94
3.3.1.3 Detection of Nonsuperconducting Second Phases (NSPs)......Page 95
3.3.1.4 Penetration Depth and Through-Thickness Examination......Page 96
3.3.1.5 Monitoring of the REBCO Formation Process......Page 97
3.3.2 Bismuth Oxide Superconductors......Page 101
3.3.3 Mercury Oxide Superconductors......Page 103
3.3.4 Thallium Oxide Superconductors......Page 107
3.3.5 The MgB2 Superconductor......Page 108
Acknowledgment......Page 110
References......Page 111
4.1 Introduction......Page 114
4.2 Ion Beam Assisted Deposition (IBAD) Process......Page 116
4.4 Rolling-Assisted Biaxially Textured Substrate (RABiTS) Based Templates......Page 118
4.6 Summary......Page 120
References......Page 122
5.1 Introduction......Page 126
5.1.1 Types of Pinning Centers......Page 127
5.1.1.4 Second-Phase Additions......Page 128
5.2.2 Premixed Targets......Page 129
5.3 Experimental Setup......Page 130
5.4.1 YBCO Films Prepared Using a YBCO Sectored PLD Target with Y2BaCuO5 and BaSnO3 Sectors......Page 131
5.4.2 Current Density and Alpha Value Variations with Temperature, and Dual Peaks in Fp Plots of YBCO+BSO Samples......Page 132
5.4.3 High-Quality YBCO+BSO Thick Films......Page 135
5.4.4 YBCO+BSO Effects of Concentrations......Page 140
5.4.5 YBCO+BSO Films on Coated-Conductor Technical Substrates (Buffered Metallic Substrates)......Page 143
5.5 Summary......Page 145
References......Page 146
6: Thallium-Oxide Superconductors......Page 150
6.1 Spray-Deposited, Tl-Oxide Films......Page 151
6.2 Electrodeposited Tl-Oxide Superconductors......Page 161
References......Page 171
7.1 The Fascinating Hg-Based High-Tc Superconductors......Page 174
7.1.1 Probing the Mechanism of Superconductivity in Hg-HTS Materials......Page 175
7.1.2 Pressure Effect......Page 178
7.1.4 Magnetic Pinning......Page 179
7.2.1 Superconductivity in Hg-HTS bulks with n>3 CuO2 Layers......Page 181
7.2.2 Doping Hg-HTSs......Page 182
7.2.3 Growth of Hg-HTS Films on Technologically Important Substrates......Page 183
7.2.5 Cation Exchange Process......Page 184
7.3.1 Microwave Passive Devices......Page 187
7.3.4 Josephson Junctions......Page 189
7.4 Future Remarks......Page 190
References......Page 191
8.1 Introduction......Page 196
8.2.1 Synthesis of Bulk MgB2......Page 198
8.2.3 Pairing Mechanism......Page 199
8.2.4 Thermodynamic Properties and Two-Gap Nature......Page 201
8.3 Tuning the Upper Critical Field......Page 206
8.4 Mg1-xAlxB2......Page 208
8.4.1 Structural Properties......Page 210
8.4.3 Evolution of Hc2 in Mg1-xAlxB2......Page 211
8.4.4 Superconducting Gaps in Mg1-xAlxB2......Page 213
8.5 Mg(B1-xCx)2......Page 214
8.5.1 Normal State Properties......Page 215
8.5.2 Thermodynamic and Transport Properties......Page 216
8.5.3 Evolution of the Superconducting Gaps......Page 219
8.5.4 Nature of Scattering in Mg(B1-xCx)2......Page 220
8.6 Neutron Irradiation of MgB2......Page 222
8.7 Comparison between Neutron-Damaged and Carbon-Doped Samples......Page 226
8.8.1 Enhancing Critical Current Densities......Page 229
8.8.2 MgB2 Wires from CVD......Page 232
8.8.3 Powder-in-Tube......Page 233
8.9 Future Directions in MgB2 Research......Page 235
References......Page 236
Index......Page 244