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arXiv · 2109.10043

Stability and superconductivity of 4d and 5d transition metal high-entropy alloys

Alexander J. Browne·Denver P. Strong·Robert. J. Cava
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Abstract

We report the synthesis of new equimolar high-entropy alloys (HEAs) formed from five or six 4d/5d transition metals that are each from a different Group of the Periodic Table. These include MoReRuRhPt and MoReRuIrPt, which have a valence electron count (VEC) of 8 and crystallise in the hexagonal close-packed (hcp) structure, making them isoelectronic and isostructural to the elements Ru and Os and the high-pressure phase of the well-known HEA CrMnFeCoNi. Analogous HEAs with VECs of 7, 6 and 5 crystallise with multiple phases, which we rationalise using the atomic size difference, ${\delta}$, and the electronegativity difference, ${\Delta}$${\chi}$, of the constituent elements. Finally, we find our hcp and mixed hcp-${\sigma}$ phase HEAs to be superconductors, and compare their critical temperatures to those of isostructural elements and other HEAs that have recently been reported.

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Alexander J. Browne, Denver P. Strong, Robert. J. Cava. 2021-09-21. Stability and superconductivity of 4d and 5d transition metal high-entropy alloys. https://arxiv.org/abs/2109.10043

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