- Courtney, T.H. and Pearsall, G.W. and Wulff, J., The influence of point defects on some superconducting properties of Nb3Sn (Cb3Sn),
Transactions of the Metallurgical Society of AIME, vol. 233 no. 1
pp. 212 - 218 .
(last updated on 2007/04/10)
The mechanism of the decrease in transition temperature of Nb3Sn was studied. Presintered Nb3Sn powder compacts were heated in a dynamic, vacuum at elevated temperatures. Loss of tin resulted from these heat treatments and transition temperature as a function of tin loss was discontinuous at a critical value of tin loss. In general, decreases in transition temperature were correlated with deviations from stoichiometry and presence of vacancies in niobium sites. The effect of vacancy distribution on the physical properties of Nb3Sn is considered. It is concluded that the close-packed atomic A chain in the A3B A15 structure must be preserved both in continuity and direction if good superconducting properties are to be obtained.