Calculation of metastable immiscibility region in the Al₂O₃–SiO₂system using molecular dynamics simulation

The metastable immiscibility region in the Al₂O₃–SiO₂system was calculated by conventional thermodynamic equations using thermodynamic parameters obtained from molecular dynamics simulation. The calculated miscibility gap has a consolute temperature of around 1500 °C at the critical composition of about 20 mol% Al₂O₃and spreads more widely towards the Al₂O₃-rich composition side than the SiO₂-rich side. The calculated miscibility gap in this study showed a fair agreement with that reported by Banet al.[T. Ban, S. Hayashi, A. Yasumori, and K. Okada, J. Mater. Res.11,1421 (1996)] calculated by a regular solution model, but the present calculated region is somewhat narrower in the Al₂O₃-rich composition side than that reported by Banet al.