A method of preparing a high temperature superconductor from an amorphous phase. The method involves preparing a starting material of a composition of Bi.sub. 2 Sr.sub. 2 Ca.sub. 3 Cu.sub. 4 Ox or Bi.sub. 2 Sr.sub. 2 Ca.sub. 4 Cu.sub. 5 Ox, forming an amorphous phase of the composition and heat treating the amorphous phase for particular time and temperature ranges to achieve a single phase high temperature superconductor.
Thermal Analysis of Micro-, Nano- and Non-Crystalline Materials: Transformation, Crystallization, Kinetics, and Thermodynamics complements and adds to volume 8 Glassy, Amorphous and Nano-Crystalline Materials by providing a coherent and authoritative overview of cutting-edge themes in this field. In particular, the book focuses on reaction thermodynamics and kinetics applied to solid-state chemistry and thermal physics of various states of materials. Written by an international array of distinguished academics, the book deals with fundamental and historical aspects of phenomenological kinetics, equilibrium background of processes, crystal defects, non-stoichiometry and nano-crystallinity, reduced glass-transition temperatures and glass-forming coefficients, determination of the glass transition by DSC, the role of heat transfer and phase transition in DTA experiments, explanation of DTA/DSC methods used for the estimation of crystal nucleation, structural relaxation and viscosity behaviour in glass and associated relaxation kinetics, influence of preliminary nucleation and coupled phenomenological kinetics, nucleation on both the strongly curved surfaces and nano-particles, crystallization of glassy and amorphous materials including oxides, chalcogenides and metals, non-parametric and fractal description of kinetics, disorder and dimensionality in nano-crystalline diamond, thermal analysis of waste glass batches, amorphous inorganic polysialates and bioactivity of hydroxyl groups as well as reaction kinetics and unconventional glass formability of oxide superconductors. Thermal Analysis of Micro-, Nano- and Non-Crystalline Materials: Transformation, Crystallization, Kinetics, and Thermodynamics is a valuable resource to advanced undergraduates, postgraduates, and researches working in the application fields of material thermodynamics, thermal analysis, thermophysical measurements, and calorimetry.
A number of promising glass forming compositions of high Tc superconducting Ba-Sr-Ca-Cu-O (BSCCO) materials were evaluated for their glass-ceramic crystallization ability. The BSCCO ceramics belonging to the class of superconductors in the Ba-Sr-Ca-Cu-O system were the focus of this study. By first forming the superconducting material as a glass, subsequent devitrification into the crystalline (glass-ceramic) superconductor can be performed by thermal processing of the glass preform body. Glass formability and phase formation were determined by a variety of methods in another related study. This study focused on the nucleation and crystallization of the materials. Thermal analysis during rapid cooling aids in the evaluation of nucleation and crystallization behavior. Melt viscosity is used to predict glass formation ability. Ethridge, E. C. and Kaukler, W. F. Marshall Space Flight Center ...
A number of compositions of ceramic oxide high T(sub c) superconductors were elevated for their glass formation ability by means of rapid thermal analysis during quenching, optical, and electron microscopy of the quenched samples, and with subsequent DSC measurements. Correlations between experimental measurements and the methodical composition changes identified the formulations of superconductors that can easily form glass. The superconducting material was first formed as a glass; then, with subsequent devitrification, it was formed into a bulk crystalline superconductor by a series of processing methods. Ethridge, Edwin C. and Kaukler, William F. and Rolin, Terry Marshall Space Flight Center PROJ. 89-04...
This collection of papers describes the synthesis, properties, characteristics and applications of the recently discovered high-temperature superconductors. Results of research activities around the world are presented.
High c oxide superconductors such as Bi(Pb)-Sr-Ca-Cu-O (BSCCO) and Y-Ba-Cu-O (YBCO) systems are usually fabricated by sintering given mixtures of raw materials. Generally, sintering processing takes a longer heating time and the products are mechanically low strength and cannot be formed into complex shapes such as a coil, a curved fine tube or a fine rod. Another way to produce the ceramics is a glass-ceramic process in which the glasses prepared by melt-quenching are reheated for crystallization. A given mixture of raw materials in BSCCO is easily melted and quenched to form a given shape of glass, while that in YBCO is not glassified.This invaluable book has been written by authors from five countries. It presents a unique way to fabricate superconducting ceramics in BSCCO by glass-ceramic processing.
