PURPOSE: To readily obtain the subject thick superconductive oxide film having a high critical current density by placing a thick film-shaped formed body composed of a powdery superconductive oxide performing incongruent melting in two or more steps on a substrate, keeping the material in a partially molten state and subsequently gradually cooling the partially molten material.
CONSTITUTION: A thick film-shaped formed body of a powdery superconductive oxide (e.g. Bi-Sr-Ca-Cu-O-based superconductive powder) performing incongruent melting in two or more steps is placed on a substrate. The powdery superconductive oxide is then heated at a temperature higher than that of partial melting thereof and lower than next incongruent melting temperature in a higher temperature region to be kept in a partially molten state and subsequently cooled at a cooling rate of ≤20°C/h. Orientation of crystalline particles constituting the thick superconductive oxide film can be improved thereby and bonding between the crystalline particles are made strong at the same time, thus enabling increase of the critical current density.
KUMAKURA HIROAKI
MAEDA HIROSHI
KASE JUNICHIRO
YANAGISAWA EIJI
MORIMOTO TAKESHI
ASAHI GLASS CO LTD