Effect of inhomogeneous distribution of critical-current density on AC susceptibility in superconducting film

Abstract

In this paper, the AC susceptibility in superconducting film is studied by the extended exponential critical state model, in which the critical-current density is assumed to be inhomogeneous distributed, namely, space gradient dependent. The results show that it should be noted that existence of the gradient parameter produces a quantitative effect on the form of the dependence of AC susceptibility. The magnetization properties caused by the gradient parameter are also highly nonlinear, which should be useful for the design of thin superconducting film devices.