Critical current of a textured granular superconductor in high magnetic fields

Abstract

The critical current density J c is studied theoretically using the cluster model of a granular superconducting structure for the case where Abrikosov vortices are present in the grains. It is found that the dependence of J c on the effective ratio of the sizes of grains forming an intergrain Josephson junction is Gaussian. The dependence of J c on the anisotropy of the penetration of a magnetic field into the grains is shown to reduce to the dependence on the coupling strength between the crystallites.