PROCESSING AND SUPERCONDUCTING PROPERTIES OF HIGH-JC BULK YBACUO PREPARED BY MELT PROCESS

The authors tried to produce high critical current density (J(c)) bulk superconducting material by a melt process. It became clear that the grain boundary region acts as a weak-link and causes the low J(c) of the sintered material. It was found that highly oriented bulk material can be produced by a melt process in Y-Ba-Cu-O system. The authors obtained samples which contained many fine Y2BaCuO5 (211) phases and no grain boundary throughout a region of several tens of cubic millimeters. By magnetization measurements, it was found that J(c) exceeded 10(4) A/cm2 at 77 K and 1 T, which is a promising value for practical applications.