Abstract:

Through the first-principles plane-wave ultrsoft pseudopotential method of density functional theory, elastic and thermodynamic properties of CaF₂ were studied based on the optimized structure. The result of calculations obtained was: lattice parameter was 0.5480nm; bulk modulus  is  C₁₁=154.4GPa, C₁₂=38.2GPa, C₄₄=29.9GPa, bulk modulus B₀ was 76.9GPa, and the Debye temperature was 489.6K according to the Debye mode approximation and the elastic constants. The heat capacity was close to the Dulong-Peti limit at the high temperature.

Key words: density function; elastic; Debye temperature; thermodynamic properties