KINETICS OF CRITICAL CURRENTS, CRITICAL-T EMPERATURE OF SUPERCONDUCTIVITY AND ELECTRICAL-CONDUCTIVITY OF NORMAL-STATE UNDER PHOTOIRRADIATION OF EPITAXIAL YBA2CU3O6+X FILM

Time dependences of critical current, I-c, critical temperature, T-c, and normal state conductivity, sigma, were measured during a prolonged exposure of the epitaxial superconductive metal-oxide film YBa2Cu3O6x to photoirradiation. It is shown that the kinetics of sigma, T-c and I-c are grown up by two processes the, time constants of which differ an one order of magnitude. A fast process is related to the increase in the number of hole Carriers, a slow one is related to the ordering of the oxygen ions in the CuOx plane with the number of carriers uncha nged. This process affects the motion of carriers in the CuO2 plane vi a the potential relief created by the impurity charges of the CuOx pla ne. Only the slow process reveals itself in the kinetics of critical t emperature T-c. Hence it follows that the high-T-c superconductivity i s related to the potential relief. It is shown that the critical curre nt in YBa2Cu3O6+x films is limited mainly by the weak links formed in the regions with reduced electrical transparency.