The present research, as a part of the OTM materials development and testing effort, examines the combined effect of the Cr: Fe ratio (7:3, 8:2 and 9:1) and oxygen partial pressure (PO2) on the densification, microstructural development, and chemical stability of lanthanum chromite (La0.8Sr0.2)(0.95)Cr1-xFexO3 (LSCrF) for application in oxygen transport membrane and solid oxide fuel cell electrode. While highest density of 96.3 (+/- 0.5) % is achieved for LSCrF with Cr: Fe ratio of 7:3 at 1400 degrees C and PO2 similar to 10(-10) atm., the relative density decreases with increase in Cr: Fe ratio and PO2. LSCrF perovskite stability increases with increase in Cr: Fe ratio in reducing gas atmosphere. LSCrF (7:3) dissociates into FeOx. and Fe1+xCr2-xO4 under reducing gas atmosphere (Ar-3%H-2-3%H2O). LSCrF (9:1) perovskite does not show any evidence of second phase (FeOx and Fe1+xCr2-xO4) formation with decrease in PO2 unlike LSCrF (7:3 and 8:2). Defect chemistry and mechanism for FeOx. and Fe1+xCr2-xO4 formation in reducing atmosphere is described. LSCrF decomposition and the formation of the secondary phases are in agreement with the thermodynamic simulation results obtained with the La-Sr-Cr-Fe-0 thermodynamic database. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.