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AssigneesInternational Superconductivity Technology Center, Hokuriku Electric Power Company, Sumitomo Electric Industries, Ltd., Kawasaki Jukogyo Kabushiki Kaisha, Nippon Steel Corporation
InventorsMasato Murakami, Tsutomu Takata, Koji Yamaguchi, Akihiro Kondoh, Naoki Koshizuka
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An oxide superconductor comprising a crystal of LnBa.sub.2 Cu.sub.3 O.sub.y (wherein Ln is at least one of rare earth elements including Y) and, finely dispersed therein, Ln.sub.2 BaCuO.sub.5 and a composite oxide of PtBaCuO having an average particle diameter of 0.1 to 10 .mu.m is disclosed. The oxide superconductor is produced by melting a raw material powder comprising a composite oxide of Ln, Ba and Cu, rapidly solidifying the melt, pulverizing the resultant solid, mixing a Pt powder with the pulverized mixture, forming a resultant mixture, heating a resultant formed body to bring the formed body to a partially-molten state and cooling the partially-molten material.
An oxide superconductor comprising a crystal of LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln is at least one element selected from the group consisting of Y, Sm, Eu, Gd, Dy, Ho, Er and Yb as an oxide superconducting phase and, finely dispersed therein, Ln.sub.2 BaCuO.sub.5 as a 211 phase and PtBa.sub.4 Cu.sub.2 O.sub.y as a composite oxide of Pt, Ba and Cu having an average particle diameter of 0.1 to 10 .mu.m.
A process for producing an oxide superconductor, which comprises mixing at least an oxide of one element selected from the group consisting of Y, Sm, Eu, Gd, Dy, Ho, Er and Yb, hereinafter referred to as "Ln", with a powder of BaCO.sub.3 and CuO to prepare a mixed powder, heating the mixed powder, and melting the mixed powder to form a molten material, rapidly cooling and solidifying the molten material to form a solidified material, pulverizing the solidified material to form a fine powder, mixing 0.2 to 2.0% by weight of a platinum powder with the pulverized fine powder, forming a body with the resultant mixture, heating the formed body to bring it to a partially-molten state and then cooling the partially-molten formed body to finely disperse Ln.sub.2 BaCuO.sub.5 as a 211 phase and a platinum compound of the formula PtBa.sub.4 Cu.sub.2 O.sub.y in a crystal of an oxide superconductor comprising LnBa.sub.2 Cu.sub.3 O.sub.y, where y is a number sufficient to permit oxide superconductivity.
A process for producing an oxide superconductor, characterized by heating a mixed powder comprised of a composite oxide of Y, Ba and Cu to a temperature in the range of from 1300.degree. to 1450.degree. C. to form a mixed phase comprising Y.sub.2 O.sub.3 and a liquid phase, rapidly cooling the mixed phase to form a solidified material, pulverizing the solidified material to provide a powder having an average particle diameter of 0.1 to 10 .mu.m, adding and mixing said powder with a platinum powder in an amount of 0.2 to 2.0% by weight, forming the mixture into a formed body, heating the formed body to a temperature in the range of from 1050.degree. to 1200.degree. C. to bring the formed body to a partially-molten state, thereby forming a mixed phase comprising a 211 phase and a liquid phase, and cooling said formed body at a rate of 0.5 to 10.degree. C./hr to disperse the 211 phase and a platinum compound of the formula PtBa.sub.4 Cu.sub.2 O.sub.4 in a crystal of LnBa.sub.2 Cu.sub.3 O.sub.y.
Dependencies are inferred from the claim text.