Study of electronic structure, elastic and thermodynamic properties of Cu2MgSnS4 under different pressures

The electronic structure, elastic and thermodynamic properties of Cu2MgSnS4 was studied based on density functional theory (DFT). The results show that Cu2MgSnS4 is a direct bandgap semiconductor. The B/G of Cu2MgSnS4 is greater than 1.75, indicating that Cu2MgSnS4 is a ductile material. Through the study of thermodynamic properties, it is found that the temperature increases, the bulk modulus B and Debye temperature Θ decrease, while the heat capacity CV, entropy S, Grüneisen constant γ and thermal expansion coefficient α increase, and the heat capacity is close to the Dulong-Petit limit. As the pressure increases, the bulk modulus B, Debye temperature Θ increases, while the entropy S, Grüneisen constant γ and heat capacity CV decrease.