Sintering of LaFeO3 ceramics

The sintering of LaFeO(3) has been studied in the temperature interval 1100-1600 degrees C in air. The effect of cation nonstoichiometry on densification, micro-structure, and phase composition is emphasized. La(2)O(3) was observed to inhibit both sintering and grain growth. In Fe-excess materials, exaggerated grain growth occurred, particularly above 1430 degrees C, where a liquid phase was formed. Postsintering swelling was observed in Fe-excess materials above 1430 degrees C, The swelling mechanism is related to phase equilibria, which are reductive in nature and lead to the evolution of oxygen gas, The density in La-excess materials remains high up to 1600 degrees C, but the ceramics might disintegrate in air.