Theoretical investigations on phase stability, elastic constants and electronic structures of Ga3Zr polymorphs under high pressure

By using density functional theory (DFT) method, the phase stability, elastic properties, Debye temperature and electronic structure of zirconium trigallide (Ga3Zr) have been investigated. The polymorphs of D0(22)- and Ll(2)-Ga3Zr are compared under various pressures from 0 GPa to 60 GPa. The results show that phase transition from D0(22)-Ga3Zr to Ll(2)-Ga3Zr will occur when pressure is over 28.48-36.34 GPa. With the pressure going up, the elastic constants, mechanical moduli and Debye temperature of both phases increase. For L1(2)-Ga3Zr, better ductility and lower Debye temperature of L1(2)-Ga3Zr is confirmed. The pressure-induced Zr-4d delocalization can strengthen its orbital hybridization with Ga(s, p), which leads to stronger atomic bonding, and subsequently makes the L1(2)-Ga3Zr more stable under high pressure. (C) 2016 Published by Elsevier B.V.