Abstract: High T.sub.c oxide superconductive films can be formed on gallate layers, where the gallate layers include a rare earth element or a rare earth-like element. Combinations of rare earth elements and rare earth-like elements can also be utilized. The superconductive films can be epitaxially deposited on these gallate layers to form single crystals or, in the minimum, highly oriented superconductive layers. Any high T.sub.c superconductive oxide material can be utilized, but the best lattice matches are to superconductive materials including copper oxides. Examples include Y-Ba-Cu-O systems, Bi-based systems and Tl-based systems.