Superconductivity in the high-entropy alloy (NbTa)0.67(MoHfW )0.33

Structural and physical properties of the high-entropy alloy (NbTa)0.67(MoHfW)0.33 were studied by x-ray powder diffraction, energy dispersive x-ray spectroscopy, magnetization, electrical resistivity, and specific heat measurements. The experimental results were supported by theoretical calculations using two complementary approaches for electronic structure calculations: the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) and projector augmented wave (PAW) within the density functional theory. It was found that the alloy forms with a cubic, body-centered structure (space group Im3m, W-type structure) with a lattice parameter a = 3.287(1) angstrom and a random (but microscopically homogeneous) distribution of the constituent elements. At high temperature the alloy exhibits simple metallic behavior, while at low temperature it becomes a type-II superconductor with the critical temperature Tc approximate to 4.3 K and the upper critical field mu 0Hc2 approximate to 1.45 T. The electron-phonon coupling constant calculated from the PAW data, lambda th-PAW the experimental results.

Automated summary

The structural and physical properties of the high-entropy alloy (NbTa)0.67(MoHfW)0.33 were investigated using experimental and theoretical methods. It was found that the alloy has a body-centered cubic structure and exhibits superconductivity at low temperatures.