ANISOTROPY OF THE TRANSPORT CRITICAL-CURRENT IN (110)-, (113)-, AND ALPHA-AXIS-ORIENTED YBA2CU3O7-DELTA THIN-FILMS

The transport critical currents of (110)-, (113)-, and a-axis-oriented YBa2Cu3O7-delta thin films were measured as a function of the magneti c-field direction at different temperatures (4.2-77 K) and magnetic fi elds (less than or equal to 1.5 T). Major peaks due to the intrinsic p inning were observed when the magnetic field was parallel to the Cu-O planes while secondary peaks due to surface pinning were only seen at high temperatures. The temperature dependence of J(c) shows different behavior in these thin films. Possible reasons for this are discussed.