Current characteristics and microstructure in a multifilamentary Nb-37Ti-22Ta superconductor

• Published in: IEEE transactions on applied superconductivity Vol. 11; no. 1; pp. 3796 - 3799
• Main Authors: Chernyi, O.V., Storozhilov, G.E., Ilicheva, V.O., Starodubov, V.D., Lazareva, M.B., Andrievskaya, N.F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-03-2001; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitive sensors; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical currents; Electric arc melting; Exact sciences and technology; Heat treatment; Kinetic theory; Magnetic fields; Microstructure; Multifilamentary superconductors; Niobium; Niobium base alloys; Physics; Plastic deformation; Plastics; Properties of type I and type II superconductors; Superconducting materials; Superconductivity; Superconductors; Temperature; Ternary alloys; Transmission electron microscopy
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/77.919891

The 210-filamentary superconductor based on Nb-37Ti-22Ta, wt.% alloy was obtained by using the electric arc melting and deformation processing. During alloy drawing we used four isochronal intermediate heat treatments at the temperature 425/spl deg/C. The total heat treatment duration was varied from 50 to 1000 hours. The true plastic strain value between heat treatments was 0.4 and after the final treatment was 3-5. The kinetics of phase transformation in the ternary alloy was investigated by the method of transmission electron microscopy. The J/sub c/ value increases with an increasing quantity of the precipitated alpha-phase in medium magnetic fields. The J/sub c/ (5 T, 4.2 K) value reaches 3000 A/mm/sup 2/ or more. In high fields, J/sub c/(10.4 T, 2.05 K) for the given superconductor was equal to 1600 A/mm/sup 2/. The parameters responsible for the shape of pinning force curve are determined for different treatment conditions.