AlH3 between 65-110 GPa: implications of electronic band and phonon structures

Abstract

A first-principles density-functional-theory method has been used to reinvestigate the mechanical and dynamical stability of the metallic phase of AlH3 between 65-110 GPa. The electronic properties and phonon dynamics as a function of pressure are also explored. We find electron-phonon superconductivity in the cubic Pm-3n structure with critical temperature Tc = 37 K at 70 GPa which decreases rapidly with the increase of pressure. Further unlike a previously calculated Tc value of 24 K at 110 GPa, we do not find any superconductivity of significance at this pressure which is consistent with experimental observation.