Preparation and patterning of YBaCuO thin films obtained by sequential deposition of CuOx/Y2O3/BaF2

Abstract
Superconducting thin films of YBaCuO were prepared by stacking layers of CuOx , Y2O3, and BaF2 onto substrates held at room temperature. The CuOx layer was obtained by oxidizing in air a previously deposited metallic Cu film. After deposition of the subsequent layers, the films were annealed at 880 °C in flowing oxygen. Samples 1 μm thick on sapphire showed an onset at Tonsetc =85 K and zero resistance at T0c =70 K; on yttria‐stabilized zirconia (YSZ), Tonsetc =90 K and T0c =80 K. Patterned films are easily obtained by applying conventional photolithographic methods to the Cu film.