[19p-212B-1~15] 11.3 Critical Current, Superconducting Power Applications

[19p-212B-10] Consideration to J_c(H, θ, T) of (RE)BCO films containing nanoprecipitates that are larger than the diameter of quantized fluxes

〇Hirofumi Yamasaki¹ (1.AIST)

Keywords:(RE)BCO thin films, nanoprecipitates, butterfly-shape

The author and coworkers measured magnetic-field-angle dependent critical current densities J_c(H, θ) of YBCO thin films, and found that nanoprecipitates larger than the diameter of quantized fluxes produced broad J_c(θ) peaks centerd at the c-axis in moderate magnetic fields of B= 0.5-2 T. These broad peaks have been reasonably explained by a simple theoretical model that considers the direct summation of core pinning interactions and the angular dependence of the coherence length. However, the broad peaks collapse in high magnetic fields, and the so-called butterfly-shaped J_c(θ) curves emerge. The author has considered the cause of such phenomena.