SOLUTION OF MGO, CAO, AND TIO2, IN ALPHA-AL2O3

Atomistic simulation methods are used to predict the preferred solution mechanisms and their associated energies. Both full- and partial-charge models are discussed. It was found that defect clustering always results in a significant lowering of the solution energies but does not change the preferred solution reaction of any of the oxides. The large size of the Ca2+ ion results not only in a higher solution energy (lower solubility) for CaO compared to MgO but also to a different preferred compensation mechanism. The predicted energy for the cosolution of MgO and TiO2 is dramatically smaller than for either oxide separately. Conversely, whereas solution of TiO2 aids the solution of CaO, additions of CaO do not support TiO2 solution.