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:
Nov. 21, 1995
Filed:
May. 27, 1993
Takahiro Wada, Tokyo, JP;
Shin-ichi Koriyama, Tokyo, JP;
Takeshi Sakurai, Tokyo, JP;
Nobuo Suzuki, Tokyo, JP;
Takayuki Miyatake, Tokyo, JP;
Hisao Yamauchi, Tokyo, JP;
Naoki Koshizuka, Tokyo, JP;
Shoji Tanaka, Tokyo, JP;
International Superconductivity Technology Center, Tokyo, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Kyocera Corporation, Kyoto, JP;
Mitsubishi Metal Corporation, Tokyo, JP;
The Tokyo Electric Power Company, Incorporated, Tokyo, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
Disclosed herein are high-temperature oxide superconductors of RBa.sub.2 Cu.sub.4 O.sub.8 type, with Ba partly replaced by Sr or Ca, or with R and Ba partly replaced by Ca and Sr, respectively, as represented by the chemical composition formula of R(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8 or R(Ba.sub.1-z Ca.sub.z).sub.2 Cu.sub.4 O.sub.8 or (R.sub.1-x Ca.sub.x) (Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8. They exhibit superconductivity at high temperatures. Especially, the last one exhibits superconductivity at a higher temperature than the former two. All of them can be made with a less amount of Ba as a deleterious substance, and the first two have improved sinterability. The best results are obtained when they are produced by the process involving the hot hydrostatic pressure treatment of the mixture of raw materials at 850.degree.-1100.degree. C. in an atmosphere composed of an inert gas and oxygen. The process permits a wider selection of Ba raw materials.