The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 08, 1993
Filed:
Sep. 05, 1991
Takahiro Wada, Katano, JP;
Yuji Yaegashi, Tokyo, JP;
Ataru Ichinose, Yokohama, JP;
Nobuo Suzuki, Koganei, JP;
Hisao Yamauchi, Nagareyama, JP;
Shoji Tanaka, Tokyo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Tohoku Electric Power Co., Inc., Miyagi, JP;
Central Research Institute of Electric Power Industry, Tokyo, JP;
The Tokyo Electric Power Co., Inc., Tokyo, JP;
International Superconductivity Technology Center, Tokyo, JP;
Abstract
The present invention provides an oxide superconductor which has a relatively high transition temperature T.sub.c. This superconductor has the chemical formula (R.sub.1-x Ca.sub.x)(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.7-z wherein R is at least one rare earth element selected from the group consisting of Tm, Yb and Lu, x is with in the range of 0.1.ltoreq..times.0.5, y is within the range of 0.1.ltoreq. y .ltoreq.0.4 and z is within the range of 0.05 .ltoreq. z .ltoreq.(x/2+0.5). The invention further provides a method for producing the oxide superconductor which comprises firing a composition of the formula (R.sub.1-x Ca.sub.x)(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.7-z wherein R is at least one rare earth element selected from the group consisting of Tm, Yb and Lu, x is within the range of 0.1 .ltoreq..times..ltoreq.0.5 and y is within the range of 0.1 .ltoreq.y .ltoreq.0.4 at a temperature of from 750.degree. C. to the melting temperature of the composition under an oxygen partial pressure P(O.sub.2) of 0.001 atm .ltoreq.P(O.sub.2) .ltoreq.0.2 atm and then heat treating the composition to adjust the oxygen loss z to 0.05 .ltoreq.z .ltoreq.(x/2+0.5).