Thickness dependence of vortex pinning in epitaxial Tl-Ca-Ba-Cu-O thin films

摘要

The critical current density inferred from magnetization hysteresis for epitaxial Tl(sub 2)Ca(sub 2)Ba(sub 2)Cu(sub 3)O(sub 10) films on LaAlO(sub 3) exhibits a pronounced increase with film thickness in the high-field, high-current regime. This thickness dependence does not extend to comparatively ''thick'' single crystals, however, suggesting that the grain boundaries play a major role in collective vortex pinning for Tl-based superconducting thin films.