Physics And Materials Science Of High Temperature Superconductors Ii

Physics and Materials Science of High Temperature Superconductors, II

Physics and Materials Science of High Temperature Superconductors, II represents the results of a fruitful dialogue between physicists and materials scientists which took place under the auspices of a NATO Advanced Study Institute in Porto Carras, Greece, between 18 and 31 August, 1991. It builds on and carries forward the success of NATO ASI 181 published in 1990. The theoretical side of the discussions reveal the basic premise of the phenomenological and Ginzburg-Landau theories of superconductivity, the implications of short coherence length, long penetration depth, the melting of flux lattices, and other matters, while the materials science includes discussions of microstructures, local inhomogeneities, deviations from ideal chemistry, the effects of systematic errors in materials preparation, the definition of imperfections, and the utilization of common materials analysis techniques. The reader will be made aware of the potential significance of Angstrom scale structural and chemical details, and the need to consider basic theoretical concepts when designing procedures to process viable, solid conductors, specifically the effects of oxygen stoichiometry and deviations from it, as well as the microstructural demands on pinning in the light of very short coherence lengths.

Physics and Materials Science of High Temperature Superconductors, IV

Five questions dominated the ARW on Physics and Materials Science of High Temperature Superconductors, of which this book forms the permanent record. Briefly, these are: (i) How close are we to a unified theory? The consensus is that we are not. (ii) Flux pinning: can it be achieved in bulk materials? Still an open question. The following three questions are related. (iii) Can grain boundary contributions be brought under control? (iv) What is the real requirement for purity and general chemistry control? (v)What is the practical outlook for bulk products - tapes and wires? One of the conclusions is that the geometry and dimensions in thin films are the key parameters that facilitate the realization of high current densities and, consequently, their commercial application. On the other hand, the very large number of poorly understood microstructural, chemical and mechanical variables involved in the preparation of bulk materials are currently prohibiting large scale commercialization of wires and tapes.

Physics and Materials Science of High Temperature Superconductors, II