Processing and Long-Range Critical Current Transport in High Temperature Superconductors

Abstract

With the discovery of ceramic high temperature superconductors (HTS), many potential applications of superconductivity which previously were prohibited by the high cost of cryogen and accompanying refrigeration systems suddenly seemed feasible. Such applications for bulk superconductors include power transmission lines, superconducting magnets, motors, generators, and magnetic energy storage systems, to name a few. However, many applications require fabrication of these brittle oxides into conductors which can carry high supercurrent densities in the presence of a magnetic field. The potential of HTS for a wide range of applications triggered many efforts to develop processing methods to fabricate these materials in the necessary forms with high critical current densities(Jc). It was soon realized that some intrinsic characteristics of HTS, such as high anisotropy and small coherence length, resulted in problems nonexistent in low temperature superconductors(LTS), and hence stifled progress toward the achievement of high Jc.