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 T_c 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 H_c2 and the critical current density J_c 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.