Preparation of YBa2Cu3O7−y films on SrTiO3 and MgO by the dipping-pyrolysis process under low-p(O2) heat treatment

Abstract

Superconducting YBa2Cu3O7−y (YBCO) films having a thickness of 1 μm were prepared on SrTiO3(100) and MgO(100) by the dipping-pyrolysis process using a low-p(O2) annealing method. Heat-treatment conditions were varied along the upper limit of the stability region of the YBCO phase. Films on SrTiO3(100) exhibited strong c-axis orientation with sharp rocking curves (FWHM = 0.8°). The highest Tc,zero of 87 K was obtained for the film heat-treated at 750 °C. On the other hand, films on MgO(100) showed broader rocking curves and their Tc's remained lower. Moreover, Ag addition was found to enhance the Tc values (Tc,zero = 91 K) of films on SrTiO3 heat-treated at 750 °C.