Superconducting Gap of Pressure Stabilized (Al 0.5 Zr 0.5 )H 3 from Ab Initio Anisotropic Migdal-Eliashberg Theory.

Motivated by Matthias' sixth rule for finding new superconducting materials in a cubic symmetry, we report the cluster expansion calculations, based on the density functional theory, of the superconducting properties of Al 0.5 Zr 0.5 H 3 . The Al 0.5 Zr 0.5 H 3 structure is thermodynamically and dynamically stable up to at least 200 GPa. The structural properties suggest that the Al 0.5 Zr 0.5 H 3 structure is a metallic. We calculate a superconducting transition temperature using the Allen-Dynes modified McMillan equation and anisotropic Migdal-Eliashberg equation. As result of this, the anisotropic Migdal-Eliashberg equation demonstrated that it exhibits superconductivity under high pressure with relatively high- T c of 55.3 K at a pressure of 100 GPa among a family of simple cubic structures. Therefore, these findings suggest that superconductivity could be observed experimentally in Al 0.5 Zr 0.5 H 3 .