Thermodynamic evaluation and modeling of the Fe–Co–O system Original Research Article

A complete critical evaluation and thermodynamic modeling of the phase diagrams and thermodynamic properties of oxide phases in the Fe–Co–O system is presented. Optimized equations for the thermodynamic properties of oxide phases are obtained which reproduce all available thermodynamic and phase equilibrium data within experimental error limits from 25 °C to above the liquidus temperatures at all compositions and oxygen partial pressures from metal saturation to 100 bar. The optimized thermodynamic properties and phase diagrams are believed to be the best estimates presently available. The database of the model parameters can be used along with software for Gibbs energy minimization in order to calculate any type of phase diagram section. New experimental results are reported for the equilibrium compositions of spinel and cobaltowustite (CW) at 1200 °C in air.