Fabrication and characterization of high-temperature superconductors

A number of fabrication methods were developed to synthesize samples in single phase bulk and thin film form. Material was produced showing high-quality resistive transitions, magnetic levitation, and x-ray diffraction patterns. Films of '123' composition were made which became superconducting after annealing in oxygen. These films were grown using ion-beam sputtering and laser ablation systems designed by the author. The process considerations and extensive characterization which led to successful fabrication recipes are detailed. Nearly each parameter in the preparation is capable of significant impact on the resulting superconductive properties. Traditionally, tunneling data have yielded detailed information about the electronic density of states and electron-phonon coupling. A tunneling study is presented of Bi2Ca1Sr2Cu2Ox single crystals. As tunneling conditions are varied, the resulting characteristics display a rich variety of behavior