How new are the high T c superconductors, as compared to the conventional low T c ones? In what sense are these oxides different from regular metals in their normal state? How different is the mechanism for high T c superconductivity from the well-known electron-phonon interaction that explains so well superconductivity in metals and alloys? What are the implications of the new features of the high T c oxides for their practical applications? This interesting book aims to provide some answers to those questions, drawing particularly on similarities between the high T c oxides and granular superconductors, which also present a short coherence length and a small superfluid density. Sample Chapter(s). Introduction (86 KB). Chapter 1: Superfluidity (329 KB). Contents: Superfluidity; Coherence Length, Penetration Depth and Critical Temperature; The Phase Transition; Phase Diagrams; Gap, Symmetry and Pseudo-Gap; Basics on Vortices; Cuprate Superconductors Under Strong Fields; From Fundamentals to Applications; HTS Conductors and Their Applications. Readership: Condensed matter physicists, researchers and engineers in applied superconductivity.
The achievement of large critical currents is critical to the applications of high-temperature superconductors. Recent developments have shown that melt processing is suitable for producing high Jc oxide superconductors. Using magnetic forces between such high Jc oxide superconductors and magnets, a person could be levitated.This book has grown largely out of research works on melt processing of high-temperature superconductors conducted at ISTEC Superconductivity Research Laboratory. The chapters build on melt processing, microstructural characterization, fundamentals of flux pinning, critical current, and applications of bulk monolithic superconductors. The text also describes the basic mechanism of levitation and its application. This book will be useful for research workers, engineers, and graduate students in the field of superconductivity.List of Authors: H Fujimoto, S Gotoh, T Izumi; N Koshizuka, K Miya, M Murakami, N Nakamura, Y Nakamura, Y Shiohara, H Takaichi, T Taguchi, M Uesaka, H W Weber, K Yamaguchi.
How new are the high c superconductors, as compared to the conventional low Tc ones? In what sense are these oxides different from regular metals in their normal state? How different is the mechanism for high Tc superconductivity from the well-known electron-phonon interaction that explains so well superconductivity in metals and alloys? What are the implications of the new features of the high Tc oxides for their practical applications? This interesting book aims to provide some answers to those questions, drawing particularly on similarities between the high Tc oxides and granular superconductors, which also present a short coherence length and a small superfluid density.
Prof. Heike Kamerlingh Onnes discovered superconductivity while measuring resistivity of mercury. Surprisingly the resistivity of mercury ceased at 4.2 K and this phenomenon was known as superconductivity. He realized the importance of this discovery in producing large magnetic fieldspl. delateIt was realized that superconductivity is in a new thermodynamic state with peculiar electric and magnetic properties. This paved the way to discover more superconductors. Simple elements such as Tin, Indium or lead showed the highest critical temperature (Tc) 7.2 K. They were called as Type 1 superconductors. Niobium-nitride was found to superconduct at 16 K at 1941 and Vanadium-silicon showed superconductive properties at 17.5 K at 1953. Nb alloys and binary or more complex compounds such as Nb3Sn (Tc – 18 K), Nb-Ti (Tc -9 K), Ga, V with Tc,23 K became type II superconductors. Thereafter, there was not much improvement in the development of superconductor although wonderful applications were expected from superconductors. After three decades, Fullerenes, like ceramic superconductors, are discovered. A decade ago MgB2 was discovered with Tc = 39 K. These superconductors were routinely produced into formof wires for producing larger magnetic fields. In all these cases cooling was effectively done by liquid Helium. A comprehensive microscopic theory of superconductivity in metals was proposed in 1957 by John Bardeen, Leon Cooper and Robert Schrieffer (the so-called “BCS” theory) for which they received the Nobel Prize in Physics. In a major breakthrough, George Bednorz and Karl Mueller discovered a brittle ceramic superconductivity in the family of cuprates at 30 K in 1986 and a new era began. Inspired by the work of Bednorz and Mueller on high temperature superconductivity (HTS), Paul Chu and his associates at the University of Houston discovered in 1987, 123 compounds. That is, YBCO (Yttrium1- Barium2-Copper3- Oxygen7) and iso-structural RBCO (Rare-earth1-Barium2-Copper3-Oxygen7) have a Tc of 93 K. Prior to 1987, all superconducting materials had lower critical temperatures (Tc’s) and therefore functioned only at temperatures near the boiling point of liquid helium (4.2 K) or liquid hydrogen (20.28 K), with the highest being Nb3Ge at 23 K. They were known as low temperature superconductors. YBCO was the first material to become superconducting above 77 K, (boiling point of liquid nitrogen) and subsequently a series of high temperature superconducting materials were discovered. These superconducting materials are widely known as High temperature superconductors as these Tc’s exceeded the limit prescribed by BCS theory. HTSCs are potentially valuable as liquid nitrogen is cheaper than liquid helium. YBCO possesses superior superconducting and physical properties. YBCO receiver coils in NMR-spectrometers have improved the resolution NMR spectrometers by a factor of 3 compared to that achievable with conventional coils. Paul Chu’s group holds the current Tc-record of 164 K in the mercury barium based cuprate superconductor under pressure. Their work led to a rapid succession of new high temperature superconducting materials, ushering in a new era in material science, chemistry and technology. Added to this the structure of Bi2Sr2Ca2Cu2O10(BiSCCO) high temperature superconductive compound having T= 110 K was reported. In 1993, mercuric-cuprates, perovskite ceramic superconductors with the transition temperatures Tc =138 K was also reported.
This book is a collection of the chapters intended to study only practical applications of HTS materials. You will find here a great number of research on actual applications of HTS as well as possible future applications of HTS. Depending on the strength of the applied magnetic field, applications of HTS may be divided in two groups: large scale applications (large magnetic fields) and small scale applications (small magnetic fields). 12 chapters in the book are fascinating studies about large scale applications as well as small scale applications of HTS. Some chapters are presenting interesting research on the synthesis of special materials that may be useful in practical applications of HTS. There are also research about properties of high-Tc superconductors and experimental research about HTS materials with potential applications. The future of practical applications of HTS materials is very exciting. I hope that this book will be useful in the research of new radical solutions for practical applications of HTS materials and that it will encourage further experimental research of HTS materials with potential technological applications.
This is the first volume of a comprehensive two-volume treatise on superconductivity that represents the first such publication since the earlier work by R. Parks. It systematically reviews the basic physics and recent advances in the field. Leading researchers describe the state of the art in conventional phonon-induced superconductivity, high-Tc superconductivity, and novel superconductivity. After an introduction and historical overview, the leaders in the special fields of research give a comprehensive survey of the basics and the state of the art in chapters covering the entire field of superconductivity, including conventional and unconventional superconductors. Important new results are reported in a manner intended to stimulate further research. Numerous illustrations, diagrams and tables make this book especially useful as a reference work for students, teachers, and researchers. The second volume treats novel superconductors.
These lectures are concerned with the application of high temperature superconductors to both passive and active high-frequency devices.The central issue addressed is the electrodynamics of granular superconductors, particularly where grain boundaries (either natural or synthetic) act as Josephson weak-links. Grain boundaries are responsible for residual dissipation and for unwanted dependence of the electromagnetic properties on ambient magnetic fields and on elevated power level. Properly controlled, similar weak-links are the key to high sensitivity dc and rf SQUIDS at readily accessible temperatures, and to modulators, mixers and detectors. Such structures may conveniently lead to superconductive electronic devices as well as coherent sources of radiation in the very far infrared.
Authored by many of the world's leading experts on high-Tc superconductivity, this volume presents a panorama of ongoing research in the field, as well as insights into related multifunctional materials. The contributions cover many different and complementary aspects of the physics and materials challenges, with an emphasis on superconducting materials that have emerged since the discovery of the cuprate superconductors, for example pnictides, MgB2, H2S and other hydrides. Special attention is also paid to interface superconductivity. In addition to superconductors, the volume also addresses materials related to polar and multifunctional ground states, another class of materials that owes its discovery to Prof. Müller's ground-breaking research on SrTiO3.
In the past two years conferences on superconductivity have been characterized by the attendance of hundreds of scientists. Consequently, the organizers were forced to schedule numerous parallel sessions and poster presentations with an almost unsurveyable amount of information. It was, therefore, felt that a more informal get-together, providing ample time for a thourough discussion of some topics of current interest in high-temperature superconductivity, was timely and benefitial for leading scientists as well as for newcomers in the field. The present volume contains the majority of papers presented at the International Discussion Meeting on High-Tc Superconductors held at the Mauterndorf Castle in the Austrian Alps from February 7 to 11, 1988. Each subject was introduced in review form by a few invited speakers and then discussed together with the contributed poster presentations. These discussion sessions chaired by selected scientists turned out to be the highlights of the meeting, not only because all the participants truly appreciated the possibility of an information exchange, but mainly because of the magnificent job done by the discussion chairmen, John A. Mydosh (Leiden), Martin Peter (Geneva) and Ken E. Gray (Argonne). First results on the just discovered Bi-superconductors and the clarification of electron resonance experiments on (123)-compounds should be mentioned in particular. The relaxed atomosphere favoring free discussions was certainly promoted by the surroundings offered in the Mauterndorf Castle, which dates back to 1253. Poster presentations and a conference banquet in historic knight's halls are certainly not found everyday in conference routines.
The purpose of this book is to offer the high-Tc community a comprehensive, state-of-the-art review on bulk processing with the hope that the book would serve in part as an updated review for expert scientists and in part as a reference/text book on processing for young scientists/graduate students and those who wish to keep track of advances and technological trends in HTSC.Readers in the superconductor science/technology/education areas will find this book prepared by the world's leading experts informative and useful.
