Anisotropy and field dependence of critical current density in YBa2Cu3O7−δ epitaxial thin film

Abstract

The critical current density Jc of the epitaxial YBa2Cu3O7−δ thin film was measured as a function of applied magnetic field H up to 6 T for three special configurations: (1) H∥c axis and H⊥J; (2) H⊥c axis and H⊥J; (3) H⊥c axis and H∥J. We observed a large anisotropy of Jc(H) between H∥c axis and H⊥c axis with H⊥J, and a very small anisotropy of Jc(H) between H∥J and H⊥J with H⊥c axis. The field dependence of the critical current density can be well described by the modified Kim–Anderson model taking into account the Kramer scaling law. The weak dependence of the transport critical current density on its orientation relative to the applied magnetic field is discussed.