Vapor pressures and vapor compositions in equilibrium with hypostoichiometric plutonium dioxide at high temperatures

Vapor pressures and vapor compositions in equilibrium with a hypostoichiometric plutonium dioxide condensed phase have been calculated for the temperature range 1500 less than or equal to T less than or equal to 4000 K. Thermodynamic functions for the condensed phase and for each of the gaseous species were combined with an oxygen-potential model to obtain the partial pressures of O2, O, Pu, PuO, and PuO2. New thermodynamic functions for the solid oxide were calculated from available information and from new estimates of the heat capacity of the liquid. Thermodynamic functions for the vapor species were calculated previously. A suitable oxygen-potential model has been used previously for the solid hypostoichiometric plutonium dioxide; this model has been extended into the liquid region using several alternative methods. The effects of these alternatives on the calculated oxygen pressures have been examined in detail