Properties of calcium fluoride up to 95 kbar: A theoretical study

摘要

We have studied the high-pressure and high-temperature behaviour of calcium fluoride (CaF₂) using molecular dynamics simulations with the Born-Mayer-Huggins potentials. The thermal (pressure-volume) equation of state, radial distribution functions (RDFs) just nearby the melting temperature, isothermal bulk modulus, and volume thermal expansion coefficients were calculated from the isobaric and isothermal ensemble. Structural and thermodynamical properties at ambient temperature were well reproduced for the cubic fluorite-type phase of CaF₂. At an extended pressure and temperature ranges, the thermal expansivity and bulk modulus of CaF₂ have also been predicted. The RDFs indicated that the melting temperature is bracketed between 1600 and 1700 K, and the thermodynamic properties of CaF₂ with fluorite-type cubic structure are investigated in the pressure range 0–95 kbar and temperature up to 1600 K.