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:
Mar. 15, 1994
Filed:
Jul. 10, 1992
Joachim Bock, Erftstadt, DE;
Eberhard Preisler, Erftstadt, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, US;
Abstract
The invention relates to a high-temperature superconductor composed of the oxides of bismuth, strontium, calcium and copper and, optionally, of lead, and having the composition Bi.sub.2-a+b+c Pb.sub.a (Sr, Ca).sub.3-b-c Cu.sub.2+d O.sub.x, where a=0 to 0.7; b+c=0 to 0.5; d=-0.1 to 0.1 and x=7 to 10 and a Sr:Ca ratio of 2.8:1 to 1:2.8 as well as of strontium and/or barium sulfates. Said superconductor can be prepared by intimately mixing the oxides of bismuth, strontium, calcium and copper and optionally of lead with strontium and/or barium sulfates, melting the mixture by heating to temperatures of 870 to 1300.degree. C., higher temperatures being required for higher strontium and/or barium sulfate contents, pouring the melt into molds and allowing it to solidify slowly therein and subjecting the moldings removed from the molds to a heat treatment at temperatures of 700 to 900.degree. C. in an oxygen-containing atmosphere.