Superconductivity in the medium-entropy alloy TiVNbTa with a body-centered cubic structure

TL;DR

This paper reports the discovery and characterization of a new medium-entropy alloy, TiVNbTa, which exhibits type-II superconductivity with a critical temperature of 4.65 K, combining experimental measurements and first-principles calculations.

Contribution

It introduces a new medium-entropy alloy superconductor with detailed experimental and theoretical analysis of its properties.

Findings

TiVNbTa is a type-II superconductor with Tc of 4.65 K.

The alloy has a body-centered cubic structure.

First-principles calculations highlight the role of d electrons near the Fermi level.

Abstract

Here we report the TiVNbTa medium-entropy alloy (MEA) superconductor with the mixed 3d - 5d elements synthesized by an arc-melting method. The TiVNbTa material has a body-centered cubic structure. The superconducting properties of TiVNbTa were studied by resistivity, magnetic susceptibility, and specific heat measurements. The experimental results show that the bulk superconducting phase transition temperature of TiVNbTa is about 4.65 K, and the upper and lower critical fields are 49.3(4) mT and 5.9(5) T, respectively, which indicates TiVNbTa is a type-II superconductor. First-principles calculations show that the d electrons of Ti, V, Nb, and Ta atoms play a significant role near the Fermi level. The results show TiVNbTa is a traditional s-wave superconductor.