The effect of Y-211 precursor particle size on the microstructure and properties of Y–Ba–Cu–O bulk superconductors fabricated by seeded infiltration and growth

Large, single grains of Y–Ba–Cu–O (YBCO) bulk superconductor composed of a YBa2Cu3O7−δ (Y-123) matrix with Y2BaCuO5 (Y-211) inclusions have been fabricated using a seeded infiltration and growth (IG) process. Y-211 precursor pellets prepared from powders containing different Y-211 particle sizes were processed by the seeded IG technique to investigate the effect of Y-211 size on the single grain microstructure. The superconducting properties of the single grains fabricated in this study are observed to correlate well with the variation in Y-211 particle size in the fully textured Y-123 phase matrix. The critical current density, Jc, in particular, has been observed to increase from 68 000 A cm−2 for a reference sample to 94 000 A cm−2 at 77 K in self-field for a sample prepared using refined Y-211 precursor powder with added platinum oxide.