MAGNETIC-FIELD DEPENDENCE OF CRITICAL-CURRENT IN YBCO-AG COMPOSITE SYSTEM

We have measured the temperature dependence of the electrical resistance, I-V and V-B characteristics of YBCO-Ag composites with 3,7 and 10 Ag wt.%. Temperature dependence of the electrical resistance reveals that the Ag has no influence on critical temperature. Magnetic hysteresis loop has been observed in V-B characteristic. The critical current distribution function was also computed. The CCD indicates a decrease of the critical current with Ag concentration increase, owing to Ag, which resides on the grain boundaries, forming a thick SNS jonction.