Reaction for high performance (Bi,Pb).sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.y composites

US5798318A · kind A · utility

Assignee

• American Superconductor Corporation · US

Inventors

• Qi Li · Mountain View, US
• William Michels · Berkeley, US
• Ronald D. Parrella · Shrewsbury, US
• Gilbert N. Riley, Jr. · Marlborough, US
• Mark D. Teplitsky · Westborough, US
• Steven Fleshler · Brookline, US

Key dates

• Filing date: May 21, 1996
• Grant date: Aug 25, 1998
• Expiry date: May 21, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S505/742

Abstract

The present invention provides a (Bi,Pb)SCCO-2223 oxide superconductor composite which exhibits improved critical current density and critical current density retention in the presence of magnetic fields. Retention of critical current density in 0.1 T fields (77 K, .perp. ab plane) of greater than 35% is disclosed. Significant improvements in oxide superconductor wire current carrying capacity in a magnetic field are obtained by subjecting the oxide superconductor composite to a post-processing heat treatment which reduces the amount of lead in the (Bi,Pb)SCCO-2223 phase and forms a lead-rich non-superconducting phase. The heat treatment is carried out under conditions which localize the lead-rich phase at high energy sites in the composite.