First-principles investigations on stability, elastic properties and electronic structures of L12-TiAl3 and D022-TiAl3 under pressure

The structure stabilities, elastic properties, and electronic structures of L12-and D022-TiAl3 under different pressures have been investigated by the first-principles. The formation energy shows that both L12-TiAl3 and D022-TiAl3 were stable at pressure up to 40 GPa. There would be a phase transition from D022 phase to L12 phase when pressure is about 25 GPa D022-TiAl3 and L12-TiAl3 satisfy the mechanical property stability, and both the stiffness and plasticity increase with the increase of pressure. The elastic anisotropy of D022 structure is larger than the L12 structure. The bonding situation and electronic properties of TiAl3 (L12 and D022) were analyzed by differential charge density and density of states (DOS) curve.