Process for making high temperature Bi-Sr-Ca-Cu oxide superconductor

US5703021A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Hans-Georg von Schnering · Aidlingen, DE
• Winfried Becker · Kelkheim, DE
• Martin Schwarz · Wien, AT
• Bernhard Hettich · Hofheim, DE
• Martin Hartweg · Erbach, DE
• Leonhard Walz · Rastatt, DE
• Thomas D. Popp · Wichita, US

Key dates

• Filing date: Jun 7, 1995
• Grant date: Dec 30, 1997
• Expiry date: Jun 7, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S505/782
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A description is given of superconducting substances having a content of Bi, Sr, Ca and Cu, and of processes for their preparation from the metal oxides within a range which is specified by the overall composition Bi.sub.a (Sr,Ca).sub.b -Cu.sub.6 O.sub.x, where a=3-24 and b=3.23-24, with an Sr/Ca atomic ratio of 1:9-9:1 and a Bi:(Ca+Sr) atomic ratio of 0.3-1.5. The transition temperature is at least 60 K. The principal phase crystallizes in the orthorhombic system. The pure compounds Bi.sub.4 (Sr,Ca).sub.4 Cu.sub.2 O.apprxeq..sub.12 and Bi.sub.4 (Sr,Ca).sub.6 Cu.sub.4 O.apprxeq..sub.20.