Fabrication and superconducting properties of Gd–Ba–Cu–O single-grain bulk with barium cerate addition

We investigated processing, microstructure and superconducting properties of Gd123 single grain bulk superconductors with a large amount of BaCeO3. The melt-textured bulk samples with compositions of Gd123 : BaCeO3 : Gd211 = 100 : 40−x : x (x = 0–40) plus 20 wt.% of Ag2O and 0.5 wt.% of Pt were fabricated in Ar–1%O2 gas. The single grain bulk samples 25 and 33 mm in diameters were obtained with the composition of x = 5–40. It was observed that BaCeO3 particles of 1–2 μm in diameters and Gd211 particles of 0.5–1 μm in diameters were dispersed in the melt-textured samples. Magnetic trapped fields of the 25 mm-sized samples with x = 10–40 were around 1 T at 77 K and the 33 mm-sized sample with x = 20 was 1.4 T at 77 K.