Frequency Dependence of Resistance and Critical Current Density for YBa₂Cu₃O_7-x Superconducting Thin Films

Abstract

YBa₂Cu₃O_7-x superconducting thin films were prepared using the Excimer laser ablation technique. The current-voltage characteristics of these films was measured under various ramp current waves with rise rates of 50A/s-10kA/s. It was shown that the resistance of the flux flow increased with current rise rate. Critical current density decreased with increasing the current rise rate. The critical current density-temperature characteristics of the YBa₂Cu₃O_7-x superconducting thin films were consistent with a proximity effect junction behavior. The frequency dependence of the critical current density was found to be attributed to the electon diffusion coefficient (electron mobility) in the normal conductor layer of the superconductor-normal conductorsuperconductor (SNS) junction.