Superconductivity of ductile Ti-Nb-Si amorphous alloys

Abstract

Amorphous superconducting alloys with high strength and good ductility have been found in rapidly quenched alloys of the Ti-Nb-Si system. Continuous ribbons of these alloys were produced about 2 mm wide and 0.04 mm thick using a modified single roller quenching apparatus. The silicon content in the amorphous alloys was limited to the range between about 13 and 21 at. % and the niobium content was in the range 0–43 at. %. The alloys containing more than 10 at. % niobium showed a superconducting transition above the liquid-helium temperature (4.2 K). The transition temperature Tc increased with increasing niobium content or with decreasing silicon content. The highest value obtained was 5.1 K for Ti45Nb40Si15. The upper critical magnetic field Hc2 and the critical current density Jc were of the order of 1.6×106 A/m at 4.2 K and 300 A/cm2 at zero applied field and 4.2 K.