Thickness and annealing dependence of the superconducting transition temperature of YBa2Cu3O7−<i>x</i> thin films on oxidized silicon and polycrystalline alumina substrates

Abstract

Superconducting thin films of YBa2Cu3O7−x in the thickness range of 0.2–0.9 μm were tested in this study. A zirconia buffer layer was used to minimize interdiffusion on oxidized silicon and polycrystalline alumina substrates. The highest zero resistance transition temperatures (85 K for oxidized silicon and 86 K for polycrystalline alumina) were obtained for the thicker films; these are the highest values reported for thin films of this superconductor on these substrates. The thickness and annealing dependence of the transition temperature suggests that interdiffusion limits the performance of the thinner samples.