Thermal stability and thermal expansion studies of cubic fluorite-type MgF2 up to 135 GPa

• The thermal expansion of MgF2 with a fluorite-type structure has been investigated.
• The quasi-harmonic Debye model is applied to take into account the thermal effect.
• Particular attention is paid to the prediction of thermal expansion for the first time.

The thermal expansion of MgF2 with a fluorite structure has been investigated at high pressures using plane-wave pseudopotential scheme within the local density approximation correction in the frame of density functional theory based on the analysis of thermal stability using classical molecular dynamics simulations up to 6500 K. To investigate the thermodynamic properties like as the P–V–T equation of state and volumetric thermal expansion coefficient αV of cubic fluorite-type MgF2 at extended pressure and temperature ranges, we apply the quasi-harmonic Debye model in which the phononic effects are considered. The P–V relationship and αV dependence of the pressure up to 135 GPa at different temperatures, and the V–T relationship and αV dependence of the temperature up to the melting temperature 1500 K at different pressures have been obtained.

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