Calcium-substituted lanthanum ferrites (La1–xCaxFeO3–δ x = 0, 0.1, 0.2, 0.3, 0.4) were synthesized in air and subsequently decomposed in reducing atmospheres. The partial pressure of oxygen (PO2) was controlled by varying the H2/H2O ratio by bubbling hydrogen/argon mixtures through water baths at controlled temperatures. Three regions of mass loss were identified as the PO2 was reduced, two of which were determined to be associated with decomposition reactions. Calcium was shown to decrease the thermal stability of the perovskite compound, but rather than incrementally increasing the required PO2 for decomposition proportional to calcium concentration, all samples partially decomposed at a single PO2. The extent of the partial decomposition was dependent on the amount of calcium substitution and temperature. The perovskite phase remaining after the partial decomposition was found to fully decompose at the same oxygen partial pressure as pure lanthanum ferrite.
Stability of Decomposition of Ca-Substituted Lanthanum Ferrite in Reducing Atmospheres was originally published by Wiley-Blackwell in Journal of the American Ceramic Society 98(9), 2881-2886. This work is provided under a Creative Commons Attribution 4.0 International license. Details regarding the use of this work can be found at: https://creativecommons.org/licenses/by/4.0/. doi: 10.1111/jace.13569
Price, Patrick M. and Butt, Darryl P.. (2015). "Stability and Decomposition of Ca-Substituted Lanthanum Ferrite in Reducing Atmospheres". Journal of the American Ceramic Society, 98(9), 2881-2886.