ANGULAR-DEPENDENCE OF TRANSPORT CRITICAL CURRENTS IN MAGNETIC-FIELDS AND FLUX-PINNING PROPERTIES IN ND2-XCEXCUO4 THIN-FILMS

The anisotropy of the transport critical current density J(c) and the volume pinning force F(p)(T,H) in Nd2-xCexCuO4 thin films were studied in magnetic fields H up to 12 T as follows. (1) At a temperature T = 4.2 K, the value of J(c)(phi) obtained in this study was smaller than that estimated by the two dimensional model. Here phi is the angle bet ween H and the ab-plane keeping the transport current I perpendicular- to H. (2) Above T = 14 K, additional peaks of F(p)(T, H) were observed at H approximately 0.1 T, which suggest that there are at least two t ypes of pinning mechanisms for H parallel-to ab-plane.