SUPERCONDUCTORS – MATERIALS, PROPERTIES AND APPLICATIONS Edited by Alexander Gabovich Superconductors – Materials, Properties and Applications http://dx.doi.org/10.5772/2577 Edited by Alexander Gabovich Contributors Guoqing Wu, W. Gilbert Clark, Chi Liang Chen, Chung-Li Dong, A.J.S. Machado, S.T. Renosto, C.A.M. dos Santos, L.M.S. Alves, Z. Fisk, Mitsuru Izumi, Jacques Noudem, Qiuliang Wang, Zhipeng Ni, Chunyan Cui, Gunzi Saito, Yukihiro Yoshida, Andrei L. Solovjov, Laureline Porcar, Patricia de Rango, Daniel Bourgault, Robert Tournier, I. Zakharchuk, P. Belova, K. B. Traito, E. Lähderanta, R. De Luca, Valerij A. Shklovskij, Oleksandr V. Dobrovolskiy, Alexander M. Gabovich, Suan Li Mai, Henryk Szymczak, Alexander I. Voitenko , Masaru Kato, Takekazu Ishida, Tomio Koyama, Masahiko Machida, Florian Loder, Arno P. Kampf, Thilo Kopp, C.A.C. Passos, M. S. Bolzan, M.T.D. Orlando, H. Belich Jr, J.L. Passamai Jr., J. A. Ferreira, Jacques Tempere, Jeroen P.A. Devreese, Dimo I. Uzunov Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2012 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Oliver Kurelic Typesetting InTech Prepress, Novi Sad Cover InTech Design Team First published October, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechopen.com Superconductors – Materials, Properties and Applications, Edited by Alexander Gabovich p. cm. ISBN 978-953-51-0794-1 Contents Preface IX Section 1 Experiment 1 Chapter 1 Field-Induced Superconductors: NMR Studies of λ–(BETS) 2 FeCl 4 3 Guoqing Wu and W. Gilbert Clark Chapter 2 X-Ray Spectroscopy Studies of Iron Chalcogenides 21 Chi Liang Chen and Chung-Li Dong Chapter 3 Defect Structure Versus Superconductivity in MeB2 Compounds (Me = Refractory Metals) and One-Dimensional Superconductors 45 A.J.S. Machado, S.T. Renosto, C.A.M. dos Santos, L.M.S. Alves and Z. Fisk Chapter 4 Improvement of Critical Current Density and Flux Trapping in Bulk High-T c Superconductors 61 Mitsuru Izumi and Jacques Noudem Chapter 5 Superconducting Magnet Technology and Applications 83 Qiuliang Wang, Zhipeng Ni and Chunyan Cui Chapter 6 Development and Present Status of Organic Superconductors 105 Gunzi Saito and Yukihiro Yoshida Chapter 7 Pseudogap and Local Pairs in High-T c Superconductors 137 Andrei L. Solovjov Chapter 8 Magnetic Texturing of High-T c Superconductors 171 Laureline Porcar, Patricia de Rango, Daniel Bourgault and Robert Tournier VI Contents Section 2 Theory 197 Chapter 9 Eilenberger Approach to the Vortex State in Iron Pnictide Superconductors 199 I. Zakharchuk, P. Belova, K. B. Traito and E. Lähderanta Chapter 10 Effective Models of Superconducting Quantum Interference Devices 221 R. De Luca Chapter 11 Microwave Absorption by Vortices in Superconductors with a Washboard Pinning Potential 263 Valerij A. Shklovskij and Oleksandr V. Dobrovolskiy Chapter 12 dc Josephson Current Between an Isotropic and a d-Wave or Extended s-Wave Partially Gapped Charge Density Wave Superconductor 289 Alexander M. Gabovich, Suan Li Mai, Henryk Szymczak and Alexander I. Voitenko Chapter 13 Composite Structures of d-Wave and s-Wave Superconductors (d-Dot): Analysis Using Two-Component Ginzburg-Landau Equations 319 Masaru Kato, Takekazu Ishida, Tomio Koyama and Masahiko Machida Chapter 14 Flux-Periodicity Crossover from hc/e in Normal Metallic to hc/2e in Superconducting Loops 343 Florian Loder, Arno P. Kampf and Thilo Kopp Chapter 15 A Description of the Transport Critical Current Behavior of Polycrystalline Superconductors Under the Applied Magnetic Field 365 C.A.C. Passos, M. S. Bolzan, M.T.D. Orlando, H. Belich Jr, J.L. Passamai Jr. and J. A. Ferreira Chapter 16 Path-Integral Description of Cooper Pairing 383 Jacques Tempere and Jeroen P.A. Devreese Chapter 17 Theory of Ferromagnetic Unconventional Superconductors with Spin-Triplet Electron Pairing 415 Dimo I. Uzunov Preface Superconductivity is a fascinating field of the solid state physics. For more than four decades since the discovery in 1911 of the first superconductor, Hg, by Heike Kamerlingh Onnes its origin was unclear. This uncommon situation was changed by the appearance of the Cooper pair concept and the creation in 1957 of the Bardeen- Cooper-Schrieffer (BCS) theory of superconductivity. Subsequent years were full of other significant discoveries in this area so that now one can consider superconductivity as the scientific industry with plenty of applications as well as the testing ground for new theories and investigation methods. Number of books devoted to the phenomenon concerned, superconducting materials and devices is enormous. A question arises: why do we need more textbooks and monographs? The answer consists in extremely rapid progress of the materials science quickly making preceding volumes obsolete. Moreover, new ideas emerge stimulated by novel materials and the intrinsic logic of the developing theoretical physics. Note, that the branches of the latter are interconnected so that, e.g., the field theory and the condensed matter physics help one another inventing sophisticated tools and bold concepts. At the same time, the experimental capabilities even of well-known methods, such as photoemission ones, steadily expand making possible to study microscopic details of the superconducting energy gap structures or magnetic vortex patterns. Thus, the represented book is an attempt (we hope, a successful one) to describe most recent events in this field. The book includes 17 chapters written by noted scientists and young researchers and dealing with various aspects of superconductivity, both theoretical and experimental. The authors tried to demonstrate their original vision and give an insight into the examined problems. A balance between theory and experiment was preserved at least from the formal viewpoint (9 and 8, respectively). I am not going to describe each of the chapters because “the proof of the pudding is in the eating”. Nevertheless, it is my duty to warn the readers that many of the problems studied here are far from being solved. In particular, it concerns my favorite pseudogap concept. It is investigated in several chapters with quite different conclusions. The reason is that such is the state of the art! X Preface I hope the book will be useful for undergraduates, postgraduates and professionals as a collection of important results and deep thoughts in the vast field of superconductivity. Alex Gabovich Leading Research Associate of Crystal Physics Department, Institute of Physics of the Ukrainian National Academy of Sciences (NAS), Ukraine . SUPERCONDUCTORS – MATERIALS, PROPERTIES AND APPLICATIONS Edited by Alexander Gabovich Superconductors – Materials, Properties and Applications http://dx.doi.org/10.5772/2577. important in type-II superconductors. Superconductors – Materials, Properties and Applications 4 However, in certain complex compounds, especially in some low-dimensional materials, superconductivity. hard copies can be obtained from orders@intechopen.com Superconductors – Materials, Properties and Applications, Edited by Alexander Gabovich p. cm. ISBN 978-953-51-0794-1