Oxygen pressures over LaMnO 3+x

Abstract

Equilibrium oxygen partial pressures over non-stoichiometric lanthanum manganite, LaMnO 3+x, have been determined by a gravimetric method at 1188–1370 K. Relative partial molar free energy, entropy and enthalpy of solution of oxygen in this phase were derived. The variation of the relative partial molar entropy of oxygen with the composition in the non-stoichiometric LaMnO 3+x phase was calculated and discussed in relation to the metal vacancy model.