Some studies on Zr- and Ti-doped multifilamentary Cu-Nb composite wires prepared by in situ techniques

Abstract

Multifilamentary superconducting wires of Cu₇₀Nb₃₀ and Cu₇₀Nb₂₉X₁ (where X = Zr and Ti) have been fabricated using the in situ technique. A small decrease in the transition temperature and an increase in both the critical current density and the upper critical field is observed for both dopants. For Zr-doped wires of diameter 0.20 mm, the critical current density is almost independent of field up to 1.5 T, after which there is a sharp drop around μ₀ H _c2. The change in the magnitude and the position of the maximum pinning force have been studied for Zr-doped wires of different diameters.