REBa.sub.2 Cu.sub.3 O.sub.7-y type oxide superconductive material having high critical current density and process for preparation thereof
AssigneeNippon Steel Corporation
InventorsMitsuru Morita, Katsuyoshi Miyamoto, Masato Murakami, Shoichi Matsuda
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Abstract
The present invention is characterized in that oxides of Y, Ba and Cu having a superconductive substance-forming composition are melted, the melt is rapidly cooled and solidified, the obtained sheet is heated at a temperature of 1000.degree. to 1350.degree. C. to produce a partially melted state thereof, and the sheet is gradually cooled at a rate lower than 200.degree. C./hr, whereby a micro-structure in which precipitates of the RE.sub.2 BaCuO.sub.5 phase having a diameter smaller than 20 .mu.m are dispersed in the REBa.sub.2 Cu.sub.3 O.sub.7-y crystal is obtained.
Claims1
An oxide superconductive material having a high critical current density of greater than 10.sup.4 A/cm.sup.2 at a temperature of 77.degree. K. and an external magnetic field of 1 Tesla, consisting essentially of an oxide of a rare earth element RE, Ba and Cu, said material exhibiting a microstructure wherein precipitate of a RE.sub.2 BaCuO.sub.5 phase, having a diameter of smaller than 20 .mu.m, are dispersed in a single crystal of a REBa.sub.2 Cu.sub.3 O.sub.7-y phase, wherein the amount of the RE.sub.2 BaCuO.sub.5 phase is from about 5% to about 35% by volume of the oxide superconductive material microstructure.
Dependencies are inferred from the claim text.