Fabrication of thin-film superconductors by bulk processing

A simple processing technique for preparation of c-axis-oriented Bi-Pb-Sr-Ca-Cu-O thin films is reported. ∼3000-Å-thick superconductor films on silver substrate have been obtained by heavy cold rolling and partial melt processing of the superconductor-silver composite structure. The films are highly textured due to the interface-induced, layer-like growth of the superconducting phase, and are essentially free of weak links. They exhibited Tc∼80 K and Jc (4.2 K) ∼104–105 A/cm2. This technique, which does not require epitaxial growth from single-crystal substrates, may be suitable for high-speed, low-cost production of large-area thin films, and points to other novel thin-film processing possibilities.