high temperature superconducting transformer seminar report

Abstract

Bednorz and Muller discovered high-temperature superconductivity in 1986. In few years many cooper oxide (cuprates) high-temperature superconductors (HTSCs) were synthesized, with a record at thallium doped, mercury based cuprate with Tc at 138K. Cuprates are layered perovskites, constructed of supercoducting, insulating and hole-donating layers. Most of them contain mixed-valence atoms, such as copper. Cuprates are all antiferromagnetic at zero level of doping and exhibit a complex phase diagram. BCS theory fails at explaining high values of Tc. Superconductive and normal phase of HTSCs exhibit completely different properties as the same phases in LTSCs. None of the proposed theories was successful although there exist a consensus about some basic properties the final theory should predict. Many application are proposed, some of them based on HTSCs properties alone, others just being advanced solutions of LTSCs applications. Magnets, SQUIDs and microwave filter devices made of
HTSCs are already in use, while many power supply and electronics devices are being tested.