The analysis on high pressure melting temperature dependence of the thermodynamic parameters of solids

Based on the relation between thermodynamic properties and temperature, one simple model has been developed to predict the melting of solids under hig h pressures. For this model, a critical temperature representing the meltin g temperature is defined, compared to the reference temperature (300 K). At any given pressure, both the reference volume (300 K) and the critical vol ume (at the melting temperature) are obtained. Then, upon the relation of t hermal pressure and temperature, the melting temperatures of solids at high -pressures can be easily calculated. Three types of solids including halide (LiF), oxide (FeO) and silicate (CaMgSi2O6) have been employed to test the reliability of the model. The obtained results indicate that the model is reliable due to a good agreement between the calculated results and the exi sting experimental melting data for lithium fluoride (LiF), diopside (CaMgS i2O6) and wustite (FeO). Also, it has been better demonstrated that our mod el is a much better and more precise method in estimating the melting of so lids at extreme pressure than the empirical melting equations. (C) 2001 Els evier Science B.V. All rights reserved.