Improved equations for addressing the high pressure melting of metastable silicate perovskites

Based on our previous thermodynamic model ol high pressure melting of any s olid that is stable under ambient pressure (Wang et al., J. Alloys Comp. 29 9 (1000) 287-291), we have derived a few equations to calculate the melting temperatures of the metastable phases synthesized at high pressures. Compa red to obtained results of high pressure melting of pyrope (Mg3Al2Si3O12) s table at ambient condition, both CaSiO3 and MgSiO3 perovskites have been us ed to calculate the melting temperatures at high pressures. The reliability of the improved model has been well demonstrated by a reasonable agreement between the calculated melting temperatures and experimental data. Compari son between obtained results with those estimated by the empirical melting equations indicates that our model is more precise than the empirical melti ng equations in extrapolating the melting the melting temperatures at highe r pressures. (C) 2001 Elsevier Science B.V. All rights reserved.