Bulk Gd-Ba-Cu-O superconductors were melt processed in air. The Gd2BaCuO5 (Gd211) particles dispersed in the melt-textured bulk could be refined by employing fine Gd211 starting powders. Since Tc of the bulk samples was lowered with decreasing the size of Gd211 particle, Jc was not improved. However, we found that a depression of Tc was prevented by Ag addition, leading to higher Jc values. The Jc of Gd-Ba-Cu-O/Ag with Gd211 particles about 0.7 μm in size exhibited 60 000 A/cm2 at 77 K and self-field.
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