Enhanced flux pinning of single grain bulk (Gd, Dy)BCO superconductors processed by cold-top-seeded infiltration growth method

Abstract

Single grain (Gd, Dy)BCO bulks were fabricated via cold-top-seeded infiltration growth process in air. Microstructural observations clarified that the size and dispersion of embedded (Gd, Dy)2BaCuO5 (211) secondary phase particles strongly varied in dependence of the grain refiners. The combined addition of Pt and CeO2 in each amount of 0.2 wt% increased the critical current density (Jcab, B‖c-axis) to 105 A/cm2 at 77 K and self-field. The microstructural and magnetic properties of Pt and CeO2 doped sample exhibited high homogeneity throughout the bulk sample. The optimum amount of Dy-211 is added to GdBCO along with Pt and CeO2 resulted in highest superconducting Jcab of 72 kA/cm2 at an applied magnetic field of 2.2 T with improved flux pinning which is confirmed by high values of the reduced fields (hmax = Ha/Hirr).