Off-axis co-sputtered YBCO and CeO/sub 2/ thin films

We have investigated the properties of off-axis co-sputtered films of YBCO and CeO/sub 2/ having CeO/sub 2/ concentrations up to 43%. Morphology investigations suggest that films with more than 29% CeO/sub 2/ may consist of a new material phase, T/sub c/ and resistance ratio decreased with increasing CeO/sub 2/ concentration. Degradation of T/sub 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/sub c/ showed two power law dependence regions with a crossover near 0.99 T/sub c/ for films having low concentrations of CeO/sub 2/. I/sub C/ 's were decreased by small applied magnetic fields, and for some samples the response was observed to increase at lower temperature. For a sample having 26% CeO/sub 2/, a 40% reduction in critical current was observed for a 2 Gauss applied field. This response indicates that this may be a candidate material for the development of Josephson vortex flow devices.