The effects of pressure on the electronic, transport and dynamical properties ofAuX2 (X = Al,Ga and In)

Abstract

The electronic band structure, transport properties, and lattice dynamics inAuX2 (X = Al,Ga and In) under high pressure have been extensively studied with fullpotential linearized augmented plane wave and pseudopotential plane wavemethods. The theoretical results for the electronic band structure and Fermisurface reveal pressure-induced electronic topological transitions (ETTs) inAuGa2 andAuIn2, while theyare absent in AuAl2, in excellent agreement with the experimental observations. Moreover, calculations ofthe transport properties at different pressures reveal subtle changes in the bandstructure close to the Fermi surface of the three intermetallic compounds. It isclear that the anomalies in transport properties are due to ETTs. Interestingly, apressure-induced soft transverse acoustic (TA) phonon mode is identified only inAuGa2. The TA phonon instability at the Brillouin zone boundaryL point might be responsible for the observed first-order phase transition at∼8 GPa.