Melt Processing of Bulk YBaCuO Superconductors With High Jc

Abstract

There are several melt processes which promote high J c in bulk YBaCuO. A comparison of various melt processes was performed in this study. It was found that size control of the Y 2 BaCuO s inclusions is the key to the improvement in J c values. IntroductionOxide superconductors are very attractive since they have high critical temperatures, which enables the use of liquid nitrogen as a coolant. However, for most applications of superconductors, critical current densities (J c 's) of 10 4 -10 6 A/cm 2 are required in the presence of significant magnetic fields. It was once believed that the J c values of oxide superconductors were intrinsically small and their applications were extremely limited [1].There are three major problems in oxide superconductors for obtaining high J c at high temperatures: (1) weak links; (2) low flux pinning force; and (3) thermal activation. As long as the superconductors are used at high temperatures, thermal