We employed Ba–Cu–O substrates for fabrication of bulk Y–Ba–Cu–O superconductors using the top-seeded melt-growth method. There were several advantages of using a Ba–Cu–O substrate as compared to conventional substrate materials such as MgO, ZrO2, Al2O3, RE123 (RE = rare earth) and RE211. The Ba–Cu–O substrate avoided crystallization from the substrate, suppressed liquid loss and scarcely reacted with the precursor. Furthermore, the introduction of large-sized cracks into a grown bulk was greatly suppressed by propagation along the interface between the grown bulk and the substrate. We were able to obtain bulk Y–Ba–Cu–O superconductors with uniform trapped magnetic field distributions and equal maximum trapped field values on both top and bottom surfaces, which indicates that the field-trapping capabilities were homogenized along the c-axes of the bulks fabricated on the Ba–Cu–O substrates.

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