First-principles Study of Structural, Elastic and Electronic Properties of Al_2Ca Phase in Mg-Al-Ca Under Pressure
The structural, elastic and electronic properties of Al2 Ca phase under pressure were determined by using CASTEP program based on the density functional theory. The calculated structural parameters at 0GPa agree well with experimental and other theoretical data. The calculated elastic properties show that the bulk modulus B, shear modulus G and Young's modulus E increase with increasing pressure, and the hardness increases. The pressure of Al2 Ca phase is below 30 GPa and the ductility and plasticity can be improved as the pressure increasing. The calculations of the density of states(DOS)show that the structural stability of Al2 Ca becomes weaker with pressure increasing from 0 to 50 GPa, but the structure remains stable and there is no induced structural phase transformation.