Phase equilibria in the Fe-Na-O system between 1100 and 1300 K

EMF measurements in electrochemical cells with an oxygen-ion-conducting solid electrolyte were used to assess the equilibrium oxygen pressure as a function of temperature in a broad composition range in the Fe-Na-O system and to map out the 1070-, 1170-, and 1270-K sections of the Fe-Na-O phase diagram. The thermodynamic model proposed for solid solutions of Na in wustite made it possible to establish a relation between the equilibrium oxygen pressure, the composition of the wustite solution, and temperature.