Properties of YBa2Cu3O7−δ multilayer films from the fluoride-based sol-gel process

Abstract

The inability to rapidly grow thick or multilayer epitaxial films for either electronic or electrical power applications limits the utility of fluoride-based processes for YBa2Cu3O7−δ (YBCO). This problem is due to the use of water vapor in the growth process, necessary for the dissociation of metallofluorides. Flowing wet gas at low temperatures is corrosive to cuprates and responsible for destroying underlying YBCO layers in attempts to grow secondary layers. This is avoided simply by increasing the temperature where vapor is introduced into the growth ambient. Resulting two-layer films of YBCO have properties similar to those of high critical current density single-layer films.