Effect of Dispersed ZrO₂ Particles on Microstructure Evolution and Superconducting Properties of Nb-Ti Alloy

The influence of dispersed ZrO₂ particles on the microstructure evolution and the superconducting properties of a Nb-Ti alloy was investigated. The studied materials were prepared by different methods including mechanical alloying (MA) and arc-melting. The obtained samples were studied by X-ray diffraction (XRD) and vibrating-sample magnetometer (VSM). It was found that ZrO₂ particles can be successively introduced into an Fe-Nb matrix by MA. However, among all prepared samples with a nominal composition of Nb-47wt%Ti-5 wt% ZrO₂, only the powders, which were prepared by MA of Nb-47wt%Ti and ZrO₂ powders, exhibit superconductivity with critical parameters comparable to those observed in pristine Nb-47wt%Ti alloy. In particular, the determined upper critical field at 0 K μ0Hc2(0) is close to 15.6(1) T. This value is slightly higher than 15.3(3) T obtained for Nb-47wt%Ti and it can be ascribed to the presence of introduced ZrO₂ particles in the Nb-Ti matrix.