Equation of state, thermoelastic properties and melting behavior of NaCl at high temperatures and high pressures

In this study, we used the Stacey reciprocal K-primed equation of state to determine the relationships with pressure, volume, and temperature for NaCl up to a temperature of 900K and pressure of 25 GPa. The bulk modulus values and pressure derivative were also obtained for the entire range of temperatures and pressures considered in this study. We investigated the thermoelastic properties of NaCl at high temperatures and high pressures using the results based on the equation of state. The pressure dependences of the thermal expansivity and Grüneisen parameter were both determined using the formulations, which satisfied the thermodynamic constraints at infinite pressure. The values of the higher-order Grüneisen parameters were obtained up to fourth order for NaCl at high pressures. The thermal expansivity values for NaCl at high pressures and high temperatures were calculated using the Anderson-Grüneisen formulation. The results obtained using the two methods were compared and discussed. The Grüneisen parameter values determined at different pressures were used to predict the melting curve for NaCl. The melting temperatures obtained at different pressures using the Lindemann-Gilvarry law agreed with the experimental data within 10%.