OFF-AXIS CO-SPUTTERED YBCO AND CEO2 THIN-FILMS

We have investigated the properties of off-axis cosputtered films of Y BCO and CeO2 having CeO2 concentrations up to 43%, Morphology investig ations suggest that films with more than 29% CeO2 may consist of a new material phase, T-c and resistance ratio decreased with increasing Ce O2 concentration, Degradation of T-c after photoresist processing the films was observed and reversed by a 20 minute oxygen plasma etch. The temperature dependence of the critical current near T-c showed two po wer law dependence regions with a crossover near 0.99 T-c for films ha ving low concentrations of CeO2. I-c's were decreased by smalt ap plie d magnetic fields, and for some samples the response was observed to i ncrease at lower temperature. For a sample having 26% CeO2, a 40% redu ction in critical current was observed for a 2 Gauss applied field. Th is response indicates that this may be a candidate material for the de velopment of Josephson vortex flow devices.