Superconducting in Equal Molar NbTaTiZr-Based High-Entropy Alloys

Abstract

Superconducting (SC) in equal molar NbTaTiZr-based high-entropy alloys (HEAs) that were added with Fe, Ge, Hf, Si, and/or V was observed. According to investigation on crystal structure, composition, and the relationship between critical temperature and e/a ratio, as indicated in Matthias’ empirical rule, the main superconducting phase was that enriched with Nb and Ta. The coherence length (ξ) that was calculated from the carrier density reveals that ξvalue has the same order of magnitude of several hundreds of Angstroms as those binary Nb-Ti and Nb-Zr alloys showed.