THE SCALING BEHAVIORS OF PINNING IN TLBACACUO SUPERCONDUCTING THIN-FILMS

Abstract

The scaling behaviors of global pinning force density in dc sputtered TlBaCaCuO superconducting thin films as functions of both reduced magnetic fields and temperatures were investigated by direct transport measurements with applied fields perpendicular to the film surface. The pinning mechanisms which were depicted by the scaling behaviors of the Tl-based thin films were found to be strongly dependent on the superconducting properties of the films. For films with high critical current densities the conventional flux line shear pinning appeared to be the predominant limiting mechanism for the current carrying capability. Whereas in more granular film that did not scale well when normalized by the extrapolated Hc2, an astonishing scaling behavior by taking a reversible field H* as the normalization parameters was observed.