Preparation of YBCO films on CeO2-buffered (001) YSZ substrates by a non-fluorine MOD method

YBa2Cu3O7-delta (YBCO) films were fabricated via a fluorine-free metal organic deposition (MOD) method followed by high-temperature, low oxygen partial pressure annealing. Trimethyl acetate salts of copper, yttrium, and barium hydroxide were used as the precursors, which were dissolved in proponic acid- and amine-based solvents. After spin-coating and burnout, samples were annealed at 740degreesC in 180 ppm oxygen partial pressure and exposed to humid atmosphere for different times. A critical transition temperature, T-c(R=O) of 90.2 K and a transport critical current density (J(c)) of 0.55 MA/cm(2) (77 K and self-field) were obtained for 0.2 mum YBCO films on CeO2-buffered yttria-stabilized zirconia (YSZ) substrates. X-ray studies shows that the YBCO films have sharp in-plane and out-of-plane texture for all samples; however, the porosity of the YBCO film varies with the time of exposure to the humid atmosphere. A reaction between YBCO and CeO2 during the high-temperature anneals and formation of the reaction product BaCeO3 was confirmed by X-ray diffraction (XRD) studies. The XRD and transmission electron microscopy analysis indicated that the epitaxial relations in the film were YBCO (001)HCeO2 (001)//YSZ (001) and YBCO [100]// CeO2 [110]//YSZ [110].