Anisotropy of the Critical Current Density and Intrinsic Pinning Behaviors of YBa_2Cu_30_y Coated Conductors

摘要

The intrinsic pinning mechanism of YBa_2Cu_30_y coated conductors was investigated in terms of the anisotropy of J_C. The dissipation in the intrinsic pinning is mainly due to the double-kink excitation of the pinned vortices in the intermediate temperature region between 70 and 40 K. In this temperature region, the n-value is as small as about 8-10. At low temperature below 20 K, however, n-values become large and J_c is independent of the magnetic field because of the reduction of the double-kink excitation of the vortices.