Superconducting Properties of Nb6Sn5 and of Multiphase Nb–Sn Alloys

Abstract

The critical temperature of Nb₆Sn₅ is less than 2.8°K and the maximum critical field is less than 600 G at 2.1°K. Since NbSn₂ also has a transition temperature below 4.2°K, Nb₃Sn is the only compound in the Nb—Sn system that is superconducting at 4.2°K. Nb₃Sn can be formed at temperatures as low as 600°C, and accounts for the observed high‐field superconductivity in multiphase alloys where Nb₆Sn₅ or NbSn₂ may be the predominant phases present.