A Simple Magnetization Technique for Determining Critical Currents in Superconducting Thin Films

We demonstrate a simple technique for determining the critical current density ( J c ) of superconducting thin films from remanent magnetization measurements. The technique provides a rapid, non-destructive measurement of J c for films of arbitrary size. J c values of both in-situ grown high-temperature superconducting thin films were determined with this technique. These J c 's were compared to direct measurements on microbridges patterned on the same film. For homogeneous films, the J c values obtained by the two techniques agree to within a factor of 2.