Oxygen ionic transport in A-site-deficient perovskites La(Pb)FeO3

Formation of perovskite-type solid solutions were found in the oxide system La1−xPbxFeO3−δ (x = 0.1–0.3). Synthesis and sintering of the ceramics at temperatures above 1300 K led to a cation deficiency in the lanthanum sublattice, due to lead oxide evaporation. Electrical conductivity and oxygen permeation fluxes were ascertained to increase with increasing x. Oxygen permeability values of the La1−xPbxFeO3−δ cation-deficient ceramics were considerably less than those of La1−xSrxFeO3−δ. Permeation fluxes through La1−xPbxFeO3−δ were demonstrated to be limited by the bulk ionic conductivity. Thermal expansion coefficients of the oxides were (10.0–10.4) × 10−6 K−1.