First-Principles Calculations of Elastic Properties of Cubic Ni₂MnGa

Dependence of bulk modulus on both pressure and temperature, the elastic constants C_ij and the pressure and temperature dependence of normalized volume V/V₀ of cubic Ni₂MnGa alloy are successfully obtained using the first-principles plane-wave pseudopotential (PW-PP) method as well as the quasi-harmonic Debye model. We analyse the relationship between bulk modulus and temperature up to 800K and obtain the relationships between bulk modulus B and pressures at different temperatures. It is found that the bulk modulus B increases monotonically with increasing pressure. Moreover, the temperature dependences of the Debye temperature are also analysed. The calculated results are in agreement with the available experimental data and the previous theoretical results.