APPEARANCE OF THREE-DIMENSIONAL SUPERCONDUCTING “VORTEX GLASS” IN Bi₂Sr₂CaCu₂O_x THIN FILMS

Abstract

The nonlinear I-V characteristics in magnetic fields at 0.12 and 0.4T of 100nm-thick Bi₂Sr₂CaCu₂O_x films on MgO(100) substrates were measured. In addition to the published results on YBa₂Cu₃O_x and Tl₂Ba₂CaCu₂O_x, the present measurement suggests that nonlinear I-V characteristics of high-T_c superconductors are universal and in agreement with a theoretical prediction based on a three-dimensional superconducting “vortex-glass” phase.