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

Abstract

We studied microstructure and superconducting properties of melt-processed RE123 (RE = Y and Dy) bulk superconductors with a large amount of BaCeO3 addition. The melttextured bulk samples with compositions of Y123 + xBaCeO3 (x = 0.05-0.4) and 0.5 wt% of Pt were fabricated in air. The BaCeO3 particles with the diameter of 1-2 µm were trapped in the melt-textured samples. The critical current density (Jc) 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(Ce0.75Zr0.25)O3 and 0.5 wt% Pt showed a high Jc value of 110 kA/cm2 at 77 K. The Dy123 bulk samples dispersed BaCeO3 and Ba(Ce0.75Zr0.25)O3 particles also exhibited excellent Jc-B properties.