Density function theory study of electronic, optical and thermodynamic properties of CaN2, SrN2 and BaN2
文摘
We put forward a first-principles density-functional theory about the impact of pressure on the structural and elastic properties of bulk CaN2, SrN2 and BaN2. The ground state properties of three alkaline earth diazenides were obtained, and these were in good agreement with previous experimental and theoretical data. By using the quasi-harmonic Debye model, the thermodynamic properties including the debye temperature ΘD, thermal expansion coefficient α, and grüneisen parameter γ are successfully obtained in the temperature range from 0 to 100 K and pressure range from 0 to 100 GPa, respectively. The optical properties including dielectric function ε(ϖ), absorption coefficient α(ϖ), reflectivity coefficient R(ϖ), and refractive index n(ϖ) are also calculated and analyzed.