Scaling Behavior Near Superconducting Transition in the YBa₂Cu₃O₇ System

Abstract

We have carried out a systematic study of the detailed I-V characteristic in magnetic fields of the YBa2Cu3O7 (YBCO) single crystals and c-axis oriented thin films. For all the samples studied, there exists a temperature at which the I-V satisfies simple power law. The I-V characteristic also follows the scaling behavior predicted by the phase transition model based on the random disorder. The derived critical exponents suggest the occurrence of 3D to 2D crossover of the flux motion. The critical field at which the crossover occurs depends on the sample thickness.