Effect of high hydrostatic pressure on structural stability of Ti 3GeC 2: A first-principles investigation

Abstract

An investigation into the structural stability, electronic and elastic properties of Ti 3GeC 2 under high hydrostatic pressure was conducted using first-principles calculations based on density functional theory (DFT). From the energy and enthalpy calculations, and the variations of elastic constants with pressure, we conclude that α ‐ Ti 3 GeC 2 is most stable upon compression to 100 GPa, which is not consistent with the nonhydrostatic in situ synchrotron X-ray diffraction studies. The higher structural stability was analyzed in terms of electronic level. The absence of band gap at the Fermi level and the finite value of the density of states at the Fermi energy reveal the metallic behavior of all polymorphs of Ti 3GeC 2.