Seeded Infiltration and Growth of Bulk YBCO Nano-Composites

The seeded infiltration and growth (SIG) technique offers near-net shape processing of bulk superconductors with significant improvement in reduced Y₂BaCuO₅ (Y-211) inclusion size, reduced shrinkage, reduced porosity and improved current density compared to samples fabricated by top seeded melt growth (TSMG). Y₂Ba₄CuMO_y phases where M = Nb, Mo, W, Ta, etc., have been shown to form nano-scale inclusions in the YBa₂Cu₃Oy (Y-123) phase matrix and to contribute to enhanced magnetic flux pinning in these materials. In this paper, we describe the introduction of Y₂Ba₄CuWO_y nano-scale inclusions into bulk superconductors processed by the seeded infiltration growth process. Critical current density, J_c, in excess of 10⁵ A/cm² at 77 K in self-field is observed for samples containing Y₂Ba₄CuWO_y.