Superconductivity in high and medium entropy alloys based on MoReRu

Hexagonal close-packed (HCP) high entropy or medium entropy alloys (HEAs or MEAs) based on alterations of the ternary superconductor Mo.33Re.33Ru.33 (valence electron count VEC = 7/atom) are tested for their potential superconductivity. Quaternary Mo.25Re.25Ru.25Rh.25 has VEC 7.5 and is superconducting at 2.5 K, implying that its electron count is too high. To decrease the VEC, Ti is added to the mixture, yielding...