The microstructure and properties of single grain bulk Ag-doped Y–Ba–Cu–O fabricated by seeded infiltration and growth

Single grain, Ag-doped Y–Ba–Cu–O bulk superconductors of up to 30 mm in diameter have been fabricated successfully by a seeded infiltration and growth (IG) technique. These samples exhibit low porosity compared with samples grown by conventional top seeded melt growth (TSMG). The density of voids within as-processed IG samples can be reduced further by adding metallic Ag, rather than Ag2O, to the Y2BaCuO5 (Y-211) pre-form. An inhomogeneous distribution of Y-211 has been observed in these samples. Finally, a maximum trapped magnetic field of 0.5 T was observed for Ag-doped Y–Ba–Cu–O of diameter 30 mm at liquid nitrogen temperature (77 K).