Magnetic Properties and Critical Currents of Epitaxial YBa₂Cu₃0_7-xFilms

Abstract

We report results for both magnetic and transport measurements on thin epitaxial films of YBa2Cu307-x which show critical current densities of 107 amps/cm2 at 4.2K. They have well formed symmetrical hysteresis loops, flux trapping effects at low fields and linear susceptibilities at low fields. Magnetic and transport critical currents are in good agreement at low temperatures. The above properties are attributed to strong pinning from point defects which are suggested to be more numerous in films than in bulk single crystals. © 1989 IEEE