First-principles Study of Electronic Structures,Elastic Properties and Thermodynamics of the Binary Intermetallics in Mg-Zn-Re-Zr Alloy

The electronic structures,elastic properties and thermodynamics of MgZn_2,Mg_2Y and Mg_2 La have been determined from the first-principle calculations.The calculated heats of formation and cohesive energies show that Mg_2La has the strongest alloying ability and structural stability.The structural stability mechanism is also explained through the electronic structures of these phases.The ionicity and metallicity of the phases are estimated.The elastic constants are calculated;the bulk moduli,shear moduli.Young's moduli,Poisson's ratio value and elastic anisotropy are derived:and the brittleness.plasticity and anisotropy of these phases are discussed.Gibbs free energy,Debye temperature and heat capacity are calculated and discussed.

The electronic structures, elastic properties and thermodynamics of MgZn2, Mg2Y and Mg2La have been determined from the first-principle calculations. The calculated heats of formation and cohesive energies show that MgzLa has the strongest alloying ability and structural stability. The structural stability mechanism is also explained through the electronic structures of these phases. The ionicity and metallicity of the phases are estimated. The elastic constants are calculated; the bulk moduli, shear moduli, Young＇s moduli, Poisson＇s ratio value and elastic anisotropy are derived; and the brittleness, plasticity and anisotropy of these phases are discussed. Gibbs free energy, Debye temperature and heat capacity are calculated and discussed.