The system MgO-AI2O3 was assessed with the CALPHAD technique using a computerized optimization procedure called PARROT. ' h o of the solid phases, MgO and spinel, showed extensive solid solubility at high temperature and were modeled with the compound energy model. The third solid phase, a-Al2O3, was modeled as a stoichiometric phase. For the liquid phase, an ionic two-sublattice model was used. In total, 13 adjustable parameters were optimized: 3 for the MgO, 8 for the spinel, and 2 for the liquid. This resulted in a consistent thermodynamic description for most of the available experimental data points on the phase diagram as well of the thermodynamic properties.

No abstract

No abstract

Experimental data on the thermodynamics and the phase diagram of the Mn-O system were reviewed, and by application of the CALPHAD method, a consistent set of thermodynamic model parameters was optimized. The phases pyrolusite (MnO 2 ), bixbyite (Mn 2 O 3 ), and hausmannite (Mn 3 O 4 ) were described as stoichiometric compounds. Manganosite (Mn 1−x O) was described using the compound-energy model and the liquid described using the two-sublattice model for ionic liquids.