Improvement in Crystal Orientation and In-plane Alignment of La-doped YBCO Thin Film on BaZrO3-buffered MgO Substrate

Abstract

Y0.9Ba1.9La0.2Cu3Oy (La-YBCO) thin films were prepared by an off-axis magnetron sputtering method on MgO substrates with and without a BaZrO3 buffer layer. Insertion of BaZrO3 buffer layer was effective for obtaining La-YBCO films with pure c-axis orientation and in-plane alignment at low temperatures below 600 °C. We prepared La-YBCO thin films on BaZrO3-buffered MgO substrates using a temperature-gradient method, in which a template La-YBCO layer was first deposited at 600 °C, and then the temperature was continuously raised to 700 °C. By this method, La-YBCO thin films with improved crystallinity were successfully prepared. It was also proved that the insertion of the BaZrO3 buffer layer enables us to prepare high-quality La-YBCO films with high reproducibility.