Contactless estimation of critical current density in thin superconducting films and its temperature dependence using ac magnetic measurements

TL;DR

This paper presents a contactless method to estimate the critical current density and its temperature dependence in thin superconducting films using ac magnetic measurements and Bean's critical-state model.

Contribution

It introduces a novel approach linking experimental ac susceptibility measurements with theoretical modeling to estimate critical current density in superconducting films.

Findings

Good agreement between experimental and model susceptibility.

Method enables contactless estimation of critical current density.

Temperature dependence of critical current density characterized.

Abstract

We have measured magnetic response of second-generation high temperature superconductor YBa2Cu3Ox wire and Nb thin film in perpendicular ac field as a function of temperature. We compare experimental complex ac susceptibility to the calculated susceptibility based on the model of Bean's critical-state response in two-dimensional (2D) disk in perpendicular field. The harmonic analysis is needed for comparison between the model and the experimental data. We present a method of linking model and experimental susceptibility. Good agreement of experimental susceptibility with model susceptibility of 2D disk allows contactless estimation of critical depinning current density and its temperature dependence.