First principles study on elastic properties, thermodynamics and electronic structural of AB2 type phases in magnesium alloy

Elastic properties, thermodynamics and electronic structures of MgNi2, MgCu2, MgZn2, Mg2Y and Mg2La have been determined from first-principle calculations. The elastic constants are calculated, the calculated bulk moduli B, shear moduli G, Youngʹs moduli E, Poisson ratio ν and elastic anisotropy AU show that MgNi2, MgCu2, MgZn2 and Mg2Y are ductile, while Mg2La is brittle; the stiffness of MgNi2 is the largest; MgZn2 is of the best plasticity among five phases; MgCu2 has the most anisotropy. Debye temperature, enthalpy, free energy, entropy and heat capacity are calculated and discussed. The calculated densities of states (DOS) show that MgZn2 has the strongest structural stability. The ionicity and metallicity of the phases is estimated, MgCu2 has the strongest ionicity and the metallicity of Mg2Y is the best.