Introduction of Hybrid APC to GdBa₂Cu₃O_y for Improving the J_c Anisotropy in Magnetic Fields

Abstract

REBCO-coated conductors are used for various power applications. For the practical use of REBCO, it is necessary to enhance the critical current density (J_c) in magnetic fields. In addition, improving the J_c anisotropy is an important issue. In this study, in order to improve J_c anisotropy, we fabricated GdBCO films incorporating a hybrid APC combined with BHO nanorods in BHO layers. From transmission electron microscopic images, we found that BHO formed nanorods along the c-axis and non-superconducting layers parallel to the ab-plane. From the magnetic field angular dependences of J_c, we found that the films exhibited two J_c peaks for B//c and B//ab, and the J_c^min showed 0.8 MA/cm² in 1 T. This value is higher than that of a film in which only nanorods are introduced. We believe that hybrid APC was effective for improving the J_c anisotropy.