Effects of Annealing Conditions and Substrate Materials on the Superconducting Properties of Ba2YCu3O7-y Films Prepared by the Dipping-Pyrolysis Process at 750°C

Abstract
Superconducting Ba2YCu3O7-y (BYCO) films were prepared on various substrates by the dipping-pyrolysis process. The effects of annealing parameters, environment and time were also investigated. The 2-µm-thick films of BaCO3-Y2O3-CuO mixture were heat-treated at 750°C under a low-oxygen partial pressure (p(O2)=2×10-4 atm) followed by annealing under higher-p(O2) atmospheres. The resulting films showed high superconducting transition temperatures; values of T c,onset(s)'s were 89 K on SrTiO3(100), 86 K on LaAlO3(100), 86 K on yttria-stabilized zirconia (YSZ), 83 K on MgO(100), and 76 K on sapphire.