Chemical Thermodynamic Considerations in Sintering of LaCrO3 ‐ Based Perovskites

The thermodynamic properties of and related compounds have been estimated and utilized to correlate sinterability with phase relations in the La‐M‐Cr‐O systems. Chemical equilibria calculations reveal that calculated vapor pressures of gaseous chromium oxides (especially ) can be well correlated with our previous experimental results on sinterability. The poor sinterability can be ascribed to the formation of a thin layer of which is formed from incongruently vaporized at the interparticle neck during the initial stage of sintering in air. Improvement of sinterability of oxides can be achieved by removing this layer or by decreasing vapor pressure to prevent the formation of layer. These suggest that perovskites are the most suitable materials for high sinterability, since these materials have the low vapor pressure without precipitation of .