Method for forming single phase, single crystalline 2122 BCSCO superconductor thin films by liquid phase epitaxy

摘要

A substantially single phase, single crystalline, highly epitaxial film of Bi.sub.2 CaSr.sub.2 Cu.sub.2 O.sub.8 superconductor which has a T. sub.c (zero resistance) of 83 K is provided on a lattice- matched substrate with no intergrowth. This film is produced by a Liquid Phase Epitaxy method which includes the steps of forming a dilute supercooled molten solution of a single phase superconducting mixture of oxides of Bi, Ca, Sr, and Cu having an atomic ratio of about 2:1:2:2 in a nonreactive flux such as KCl, introducing the substrate, e.g., NdGaO.sub. 3, into the molten solution at 850° C., cooling the solution from 850° C. to 830° C. to grow the film and rapidly cooling the substrate to room temperature to maintain the desired single phase, single crystalline film structure.