Solid solutions with La1-xCaxFeO3-delta (0 <= x <= 0.7) perovskite-like structure prepared via Pechini route have been investigated by using high resolution transmission electron microscopy and X-ray diffraction. Extended planar defects lying in (1 0 1) crystallographic planes and alpha-Fe2O3 nanoparticles on the surface of perovskite microcrystals are characteristic of the samples under investigation. It was found that testing of the samples in catalytic deep CH4 oxidation process results in partial destruction of solid solutions with formation of planar defects in the bulk and alpha-Fe2O3 particles on the surface. (C) 2015 Elsevier Ltd. All rights reserved.