Article comprising a superconductor/insulator layer structure, and method of making the article

US5364836A · kind A · utility

Assignee

• AT&T Bell Laboratories · US

Inventors

• Robert C. Dynes · Village of La Jolla, US
• Elliot H. Hartford, Jr. · Morristown, US
• Eric S. Hellman · Montclair, US
• Andrew Pargellis · Hoboken, US
• Fred Sharifi · Niskayuna, US

Key dates

• Filing date: Mar 8, 1993
• Grant date: Nov 15, 1994
• Expiry date: Mar 8, 2013

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/24926

Abstract

Disclosed is an article that comprises a superconductor-insulator (s-i) layer structure. The superconductor material has nominal composition Ba.sub.1-x M.sub.x BiO.sub.3-y (M is K, Rb, or K and Rb, 0.35<x.ltorsim.0.5, 0<y.ltorsim.0.25). In some preferred embodiments the insulator is a Ba- and Bi containing oxide, exemplarily BaBi.sub.2 O.sub.4, Ba.sub.1-x M.sub.x BiO.sub.3 (0.ltoreq.x<0.35), or Ba.sub.1-x Bi.sub.1+x O.sub.3 (0.ltoreq.x.ltorsim.0.5). In other embodiments the insulator is an insulating oxide with the NaCl structure (e.g., Mg.sub.1-x Ca.sub.x O), an insulating perovskite (e.g., BaZrO.sub.3 ), an insulator with the K.sub.2 NiF.sub.4 structure (e.g., Ba.sub.2 PbO.sub.4), an insulating fluoride with the BaF.sub.2 structure (e.g., Ba.sub.1-x Sr.sub.x F.sub.2), or an insulating fluoride with the NaCl structure (e.g., LiF). Disclosed are also advantageous methods of making an article according to the invention. S-i layer structures can form substantial ideal BCS superconducting tunnel junctions at temperatures that can be reached without the use of liquid He, typically with a closed cycle refrigerator.