Preparation of superconducting Y-Ba-Cu-O films by a reactive plasma evaporation method

Y-Ba-Cu-O superconducting films were prepared by a reactive plasma evaporation method, in which mixed powders were coevaporated in a thermal radio-frequency Ar+O2 plasma and the ternary composition controlled high-temperature metallic vapors were codeposited onto a substrate. The deposition rate was much more than 10 μm/min, which is several orders of magnitude higher than those reported by the other methods previously. The structure of the prepared films was identified as an orthorhombic oxygen-deficient perovskite phase and some films showed the preferred orientation of (001). The as-deposited film without post-annealing showed a superconducting transition temperature Tcm (midpoint) of 94 K.