Preparation of Superconducting Ba2YCu3O7-y Films by the Dipping-Pyrolysis Process at 700° and 750°C

Superconducting Ba2YCu3O7-y (BYCO) films were prepared by the dipping-pyrolysis process using metal acetylacetonates as starting materials through heat treatments below 800°C under controlled low oxygen partial pressures (p(O2)'s) followed by O2 annealing. Values of T c,zero(r)'s were greatly dependent on the temperature and p(O2) of heat treatment; they were 64 K and 85 K with the heat treatments at 700° and 750°C, respectively, under an initial p(O2) of 2×10-4 atm for 2-µm-thick BYCO films. Moreover, silver precoating was effective for improving the superconducting and surface properties of the films heat-treated at 700°C.