Microstructure and superconducting properties of meltprocessed RE-Ba-Cu-O with dispersed barium cerate particles

We studied microstructure and superconducting properties of melt-processed RE123 (REY and Dy) bulk superconductors with a large amount of BaCeO₃ addition. The melttextured bulk samples with compositions of Y123 + xBaCeO ₃ (x0.05-0.4) and 0.5 wt% of Pt were fabricated in air. The BaCeO₃ particles with the diameter of 1-2 νm were trapped in the melt-textured samples. The critical current density (J_c) in a low field region increased with the amount of BaCeO₃ inclusions. This suggests the BaCeO₃ particles act as effective flux pinning centers, as well as Y211 particles in conventional melt-textured Y-Ba-Cu-O bulk materials. We found that the size of BaCeO₃ particles could be reduced by substituting Zr on Ce site. The Y123 bulk sample with 30 mol% of Ba(Ce_0.75Zr_0.25)O₃ and 0.5 wt% Pt showed a high J_c value of 110 kA/cm² at 77 K. The Dy123 bulk samples dispersed BaCeO₃ and Ba(Ce_0.75Zr_0.25)O ₃ particles also exhibited excellent J_c-B properties.