REDUCED YSZ DEPOSITION TEMPERATURES FOR YBA2CU3OX YSZ THIN-FILMS ON SAPPHIRE/

Thin films of Y-stabilized ZrO2 (YSZ) were deposited by RF diode sputt ering on R-plane sapphire as a buffer layer for the deposition of YBa2 Cu3Ox (YBCO). By increasing the partial pressure of oxygen in the sput ter gas mixture from 20% to 50%, it was found that the substrate tempe rature required to obtain (100) oriented YSZ deposition could be lower ed to 630 degrees C from 800 degrees C. This change is attributed to h eating or mixing effects at the film surface, due to an increase in ne gative ion bombardment, which supplements the effects of external heat ing. Increases in the partial pressure of-oxygen beyond 50% were found to be counterproductive. YBCO films, deposited on the YSZ buffer laye rs via magnetron sputtering, showed c-axis orientation and transition temperatures of 82 K, Orientation of both the YSZ and YBCO films was c onfirmed by x-ray diffraction and SEM characterization.