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High-temperature superconductivity

About: High-temperature superconductivity is a research topic. Over the lifetime, 7263 publications have been published within this topic receiving 175377 citations. The topic is also known as: high-temperature superconductivity.


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31 Mar 2006
TL;DR: In this paper, the authors introduce the concept of superconductivity in high-temperature superconductors (HTSCs) and propose a method to calculate the critical current of a HTSC.
Abstract: Preface. 1. Fundamentals. 1.1 Introduction to Superconductivity in High-temperature Supersconductors (HTSCs). 1.1.1 Introductory Remarks. 1.1.2 Internal Nomenclature. 1.1.3 Critical Currents and Flux Motion in Superconductors. 1.1.4 Magnetization Curve of a Type II Superconductor. 1.1.5 Determination of Critical Currents from Magnetization Loops. 1.1.6 Magnetic Relaxation. 1.1.7 Electric Field-Current Relation. 1.1.8 Peculiarities of HTSCs in Comparison to Low-Temperature Superconductors. 1.1.9 Basic Relations for the Pinning Force and Models for its Calculation. 1.2 Features of Bulk HTSCs. 1.2.1 Bulk HTSCs of Large Dimensions. 1.2.2 Potential of Bulk HTSC for Applications. 1.3 Solid-State Chemistry and Crystal Structures of HTSCs. 1.3.1 Crystal Structures and Functionality. 1.3.2 Chemistry and Doping. 1.3.3 Intrinsic Doping: Variations of Stoichiometry. 1.3.4 Defect Chemistry. 1.3.5 Extrinsic Doping. 2. Growth and Melt Processing of YBa2Cu3O7. 2.1 Physico-Chemistry of RE-Ba-Cu-O Systems. 2.1.1 Phase Diagrams and Fundamental Thermodynamics. 2.1.2 Subsolidus Phase Relationships. 2.1.3 The Influence of Oxygen on Phase Equilibria: the System Y-Ba-Cu-O. 2.1.4 The Oxygen Nonstoichiometry in 123 phases: YBa2Cu3O7-delta (YBa2Cu3O6+x). 2.1.5 Phase Relationships in Y-Ba-Cu-O in the solidus and Liquidus Range. 2.1.6 Phase Relationships and the Liquidus Surface in Systems Ln-Ba-Cu-O (Ln=Nd,Sm,..). 2.1.7 Additional Factors. 2.2 Preparation of Polycrystalline RE123 Materials. 2.2.1 Synthesis of HTSC Compounds. 2.3 Growth of YBa2Cu3O7 Single Crystals. 2.4 Processing of "Melt-Textured" YBaCuO Bulk Materials. 2.4.1 Experimental Procedure. 2.4.2 Mass Flow, Growth Rates, Kinetic and Constitutional Undercoding. 2.4.3 Developing Microstructures: Morphology, Inclusions, Defects. 2.5 Modified Melt Crystallization Processes For YBCO. 2.5.1 Variants of the YBa2Cu3O7-Y2BaCuO5 Melt-Texturing Process. 2.5.2 Processing Mixtures of Y123 and Yttria. 2.5.3 Processing in Reduced Oxygen Partial Pressure. 3. Pinning-Relevant Defects in Bulk YBCO. 4. Properties of Bulk YBCO. 4.1 Vortex Matter Phase Diagram of Bulk YBCO. 4.1.1 Irreversibility Fields. 4.1.2 Upper Critical Fields. 4.1.3 Vortex Matter Phase Diagram. 4.2 Critical Currents and Pinning Force. 4.2.1 Transport Measurements. 4.2.2 Magnetization Measurements. 4.3 Flux Creep. 4.3.1 Flux Creep in Bulk YBCO. 4.3.2 Reduction of Flux Creep. 4.3.3 Pinning Properties from Relaxation Data. 4.4 Mechanical Properties. 4.4.1 Basic Relations. 4.4.2 Mechanical Data for bulk YBCO. 4.5 Selected Thermodynamic and Thermal Properties. 4.5.1 Symmetry of the Order Parameter. 4.5.2 Specific Heat. 4.5.3 Thermal Expansion. 4.5.4 Thermal Conductivity. 5. Trapped Fields. 5.1 Low-Temperature Superconductors. 5.2 Bulk HTSC at 77 K. 5.3 Trapped Field Data at 77 K. 5.4 Limitation of Trapped Fields in Bulk YBCO at Lower Temperatures. 5.4.1 Magnetic Tensile Stress and Cracking. 5.4.2 Thermomagnetic Instabilities. 5.5 Magnetizing Superconducting Permanent Magnets by Pulsed Fields. 5.6 Numerical Calculations of the Local Critical Current Density from Field Profiles. 5.6.1 Inverse Field Problem: Two-Dimensional Estimation. 5.6.2 Three-Dimensional Estimation. 5.7 Visualization of Inhomogeneities in Bulk Superconductors. 6. Improved YBa2Cu3O7-delta Based Bulk Superconductors and Functional Elements. 6.1 Improved Pinning Properties. 6.1.1 Chemical Modifications in YBa2Cu3O7. 6.1.2 Sub-Micro Particles Included in Bulk YBCO. 6.1.3 Irradiation Techniques. 6.2 Improved Mechanical Properties in YBa2Cu3O7-delta/Ag Composite Materials. 6.2.1 Fundamentals of the Processing and Growth of YBCO/Ag Composite Materials. 6.2.2 Processing and Results. 6.2.3 Properties of Bulk YBaCuO/Ag Composite Materials. 6.3 Near Net Shape Processing: Large Sized Bulk Superconductors and Functional Elements. 6.3.1 Finishing and Shaping. 6.3.2 The Multi-Seed Technique. 6.3.3 Rings of 123 Bulk Materials. 6.3.4 Joining of Separate Single Grains. 6.4 Bulk Materials and Processing Designed for Special Applications. 6.4.1 Infiltration Technique and Foams. 6.4.2 Long-Length Conductors and Controlled-Resistance materials. 6.4.3 Bi2212 Bulk Materials and Rings. 6.4.4 Batch Processing of 123 Bulk Materials. 7. Alternative Systems. 7.1 Impact of Solid Solutions Ln1+yBa2-yCu3O7 delta on Phase Stability and Developing Microstructure. 7.2 Advanced Processing of Ln123. 7.2.1 Oxygen Potential Control. 7.2.2 Oxygen-Controlled Melt Growth Process (OCMG). 7.2.3 Isothermal Growth Process at Variable Oxygen Partial Pressure (OCIG). 7.2.4 Composition Control in Oxidizing Atmosphere for Growing (CCOG). 7.3 Alternative Seeding Techniques. 7.4 Further LnBa2Cu3O7-Based Materials. 7.5 Ag/LnBaCuO Composites with Large Lanthanide Ions. 7.5.1 Fundamentals of Processing. 7.5.2 Reactions Near the Seed-Melt Interface. 7.5.3 Growth and Properties of Ag/LnBaCuO Composites. 8. Peak Effect. 8.1 Peak Effect (due to Cluster of Oxygen Vacancies) in Single Crystals. 8.2 Peak Effect in Bulk HTSC. 9. Very High Trapped Fields in YBCO Permanent Magnets. 9.1 Bulk YBCO in Steel Tubes. 9.1.1 Magnetic Tensile Stress (in Reinforced YBCO Disks). 9.1.2 Trapped Field Measurements. 9.2 Resin-Impregnated YBCO. 9.3 Trapped Field Data of Steel-reinforced YBCO. 9.4 Comparison of Trapped Field Data. 10. Engineering Aspects: Field Distribution in Bulk HTSC. 10.1 Field Distribution in the Meissner Phase. 10.1.1 Field Coding. 10.1.2 Zero-Field Cooling. 10.2 Field Distribution in the Mixed State. 10.2.1 Field Cooling. 10.2.2 Zero-Field Cooling. 11. Inherently Stable Superconducting Magnetic Bearings. 11.1 Principles of Superconducting Bearings. 11.1.1 Introduction to Magnetic Levitation. 11.1.2 Attributes of Superconducting Magnetic Bearings with Bulk HTSC. 11.2 Forces in Superconducting Bearings. 11.2.1 Forces in the Meissner and the Mixed State. 11.2.2 Maximum Levitational Pressure in Superconducting Bearings. 11.3 Force Activation Modes and magnet Systems in Superconducting Bearing. 11.3.1 Cooling Modes. 11.3.2 Operational Field Cooling with an Offset. 11.3.3 Maximum Field Cooling Mode. 11.3.4 Magnet Systems for Field Excitation in Superconducting Bearings. 11.3.5 Force Characteristics. 11.4 Optimized Flux Concentration Systems for Operational-Field Cooling (OFCo). 11.4.1 Stray Field Compensation. 11.4.2 Dimensional Optimization of System Components. 11.5 Parameters Influencing the Forces of Superconducting Bearings. 11.5.1 Critical Current Density. 11.5.2 Temperature. 11.5.3 Flux Creep. 11.5.4 HTSC Bulk Elements Composed of Multiple Isolated Grains. 11.5.5 Number of Poles of the Excitation System. 11.6 Applications of Superconducting Bearings. 11.6.1 Bearings for Stationary Levitation. 11.6.2 Bearings for Rotary Motion. 11.6.3 Bearing for Linear Motion. 11.7 Specific Operation Conditions. 11.7.1 Precise Positioning of Horizontal Rotating Axis. 11.7.2 Bulk HTSCs Cooled Below 77 K. 11.7.3 Cooling the Excitation System along with the Superconductor. 11.7.4 Dynamics of Rotating Superconducting Bearings. 11.8 Numerical Methods. 11.8.1 Perfectly Trapped Flux Model (2D). 11.8.2 Perfectly Trapped Flux Model (3D). 11.8.3 Vector-Controlled Model (2D). 12. Applications of Bulk HTSCs in Electromagnetic Energy Converters. 12.1 Design Principles. 12.2 Basic Demonstration for Application in Electrical Machines - Hysteresis or Induction Machines. 12.3 Trapped-Field Machine Designs. 12.4 Stator-Excited Machine Designs with Superconducting Shields - The Reluctance Motor with Bulk HTSC. 12.5 Machines with Bulk HTSCs - Status and Perspectives. 13. Applications in Magnet Technologies and Power Supplies. 13.1 Superconducting Permanent Magnets with Extremely High Magnetic Fields. 13.1.1 Laboratory Magnets. 13.1.2 Magnetic Separators. 13.1.3 Sputtering Device. 13.1.4 Superconducting Wigglers and Undulators. 13.2 High-Temperature Superconducting Current Leads. 13.3 Superconducting Fault Current Limiters. 13.3.1 Inductive Fault Current Limiters. 13.3.2 Resistive Superconducting Fault Current Limiters. 13.3.3 Status of High AC Power SFCL Concepts. 13.4 High Temperature Superconducting Magnetic Shields. List of Abbreviations. Index.

109 citations

Journal Article
TL;DR: In this article, the Fermi surface of a Fe-based superconductor, LaFePO, has been studied and extensive measurements of quantum oscillations have been carried out to obtain a detailed calliper of the size and shape of the surface.
Abstract: The recent discovery of superconductivity in ferrooxypnictides, which have a maximum transition temperature intermediate between the two other known high temperature superconductors MgB{sub 2} and the cuprate family, has generated huge interest and excitement. The most critical issue is the origin of the pairing mechanism. Whereas superconductivity in MgB{sub 2} has been shown to arise from strong electron-phonon coupling, the pairing glue in cuprate superconductors is thought by many to have a magnetic origin. The oxypnictides are highly susceptible to magnetic instabilities, prompting analogies with cuprate superconductivity. Progress on formulating the correct theory of superconductivity in these materials will be greatly aided by a detailed knowledge of the Fermi surface parameters. Here we report for the first time extensive measurements of quantum oscillations in a Fe-based superconductor, LaFePO, that provide a precise calliper of the size and shape of the Fermi surface and the effective masses of the relevant charge carriers. Our results show that the Fermi surface is composed of nearly-nested electron and hole pockets in broad agreement with the band-structure predictions but with significant enhancement of the quasiparticle masses. The correspondence in the electron and hole Fermi surface areas provides firm experimental evidence that LaFePO, whilst unreconstructed, liesmore » extremely close to a spin-density-wave instability, thus favoring models that invoke such a magnetic origin for high-temperature superconductivity in oxypnictides.« less

109 citations

Book ChapterDOI
01 Jan 1996

108 citations


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No. of papers in the topic in previous years
YearPapers
202334
202258
202169
202084
201987
201883