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:
Dec. 07, 1999
Filed:
Mar. 24, 1998
Yasuo Watanabe, Tokyo, JP;
Akihiko Endo, Tokyo, JP;
Takateru Umeda, Tokyo, JP;
Yuh Shiohara, Tokyo, JP;
Shoji Tanaka, Tokyo, JP;
Superconductivity Research Laboratory, Tokyo, JP;
The University of Tokyo, Tokyo, JP;
Abstract
There is provided a method for stably preparing rare earth (RE) 123 type oxide superconductors exhibiting outstanding superconductive properties in the atmosphere. In the method for preparing RE 123-type oxide superconductors by melting, cooling and solidifying a starting composition containing one or more than two kinds of RE such as Y, Sm, Nd, etc., and Ba, Cu and O as constituent elements to crystallize the RE 123-type oxide superconductors, the quantity of replacement between RE and Ba in 'RE 123 crystals to be formed' is controlled by changing the initial constitution of the starting composition, for example, by changing the initial constitution to a more Ba-rich side than a composition on a 123-211 (or 422) tie line on a phase diagram to yield RE 123-type oxide superconductors in the atmosphere, which exhibits a critical temperature of 90 K or above and higher critical current density (Jc) in a magnetic field. A trace amount of Pt or CeO.sub.3 may be added to micronize the 211 (or 422) phase so as to further improve Jc.