Abstract
Phase equilibria in the manganowüstite (Fe, Mn) O system were established at 1260°K by varying the oxygen partial pressure from 10-20 to 10-10 atm., by using CO2-H2 gas mixtures. The nonstoic hiometry of (Fe, Mn) O has been determined by chemical analyses. Lattice constants and Néel temperature measurements were made on these nonstoichiometric manganowustites.
The theoretical formulas showing the equilibrium relation between the gas phase and the manganowüstite phase were calculated from the statistico-thermodynamics. The formulas thus obtained were in fairly good agreement with the experimental results obtained by the present authors and by Muan et al..
