STUDY OF INTERFACES AND SURFACES OF YBa_2Cu_3O_(7-x)-Ag

Interfaces and surfaces of YBa_2Cu_3O_(7-x)(YBCO)-Ag have been studied by SEM-EDX and AES.No effect of Ag on 123 structure in X-ray diffraction pattern was observed for 0.4 mol Ag doped YBCO.AES analysis indicated that Ag segregated on surface of YBCO and resulted in decrease of YBCO-metal lead resistance.In addition,solution and segregation of Ag as elemental state were often appeared on interfaces and surfaces of high temperature annealed YBCO,whether elemental Ag or compound Ag_2O and AgNO_3 adopted as doping material.