Synthesis and structure of nanocrystalline La0.50Ba0.50MnO3

Nanocrystalline manganite La0.50Ba0.50MnO3 was synthesized by the soft-chemical method. For this purpose, the sol-gel method was modified and improved. A trihydric saturated alcohol, e.g., glycerol, was suggested as a new organic matrix. The crystal structure of the composite was studied by X-ray powder diffraction at room temperature. A La0.50Ba0.50MnO3 powder annealed in air at T = 500oC is characterized by a perovskite-like cubic structure with the unit-cell parameter a = 3.869 A. The chemical composition of the sample was studied by electron-probe X-ray microanalysis. The La: Ba: Mn cation ratio in the material was 1: 1: 2. The surface topography was examined with a scanning electron microscope. The crystallite size was ∼30 nm. The dependence of the crystal structure and the surface topology on the annealing temperature was studied. The high-temperature treatment in air resulted in the growth of larger, micrometer-size, crystallites.