Process for the preparation of superconducting compound materials

摘要

A process for the preparation of a compound material composed of a substrate and a metallic layer of a metastable or unstable phase strongly adhering to the substrate surface. This phase contains more than one elemental component, and is deposited onto the substrate from the gas or vapor phase. In this process: (a) the components used for formation of the metastable or unstable phase are very pure, having an impurity concentration of less than 100 ppm by weight; (b) during initial deposition of the layer, up to a thickness of about 5 to 20 nm, the mobility of the components on the substrate is reduced to promote germination; and (c) the components are subsequently deposited for the remainder of the layer up to the desired thickness, onto the substrate which is heated.