Superconducting Properties of V₂(Hf,Zr) Laves Phase Multifilamentary Wires

Abstract

V₂Hf-based Laves phase compounds are very attractive superconductors for fusion reactor magnet use due to their promising combination of high upper critical fields, μ_oH_c2, exceeding 20 T at 4.2 K¹ and insensitive superconductivities to both neutron irradiation² and mechanical strains³. A ternary Laves phase compound V₂(Hf,Zr) exhibits higher values of μ_oH_e2 and superconducting transition temperature, T_c, than those of the binary Laves phase compounds V₂Hf and V₂Zr, and can be formed by the diffusion reaction between Zr-Hf alloy and vanadium which are both ductile component⁴. We have already reported that V₂(Hf,Zr) can be fabricated into multifilamentary wires by the composite process using V-lat%Hf alloy matrix and Zr-(25,35,40)at%Hf alloy cores and that the V₂(Hf,Zr) multifilamentary wires show large critical current densities, J_c, in high magnetic fields⁵.