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 Jc and the volume pinning force Fp(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 Jc(φ) obtained in this study was smaller than that estimated by the two dimensional model. Here φ is the angle between H and the ab-plane keeping the transport current I perpendicular to H. (2) Above T = 14 K, additional peaks of Fp(T,H) were observed at H ∼ 0.1 T, which suggest that there are at least two types of pinning mechanisms for H parallel ab-plane. (orig.)