Study of the Microstructure Formation of Perovskite-Like Oxides in the LaMnO3–LaFeO3 System

Abstract

Solid solutions of the nominal composition La_1–y□_yMn_1–xFe_xO_3±δ (y = 0, 0.1, 0.2, x = 0.5, 0.55, 0.58) with the non-stoichiometric concentration of La cations are synthesized by the polymer-salt composition method and characterized by a set of physicochemical techniques. An increase in the degree of Fe cation doping is shown to decrease the particle size of solid solutions with retaining the perovskite structure. Particle enrichment with Fe cations and the presence of disordered crystal structure layers on the perovskite phase surface is detected by high-resolution transmission electron microscopy. According to the thermogravimetric data, the composition with x = 0.58 is characterized by a smaller weight loss, which seems to be due to the partial blocking of the perovskite phase surface by disordered layers enriched with Fe.