Investigation of the Microstructure Features of the Solid Solutions La1-xCaxCoO3-δ in Different Gas Environment
HRTEM and XRD methods are used to study the microstructure of La1–xCaxCoO3-δ perovskite-like oxides synthesized by pyrolysis of polymerized complex precursor in different gas environment. The XRD data show that the samples studied are single-phase solid solutions for x≤0.5. In situ heating of samples up to 900°C in air does not lead to noticeable changes in the samples structure, which indicates their high thermal stability. Heating in vacuum up to 900°C leads to partial decomposition of the samples. After methane oxidation reaction the formation of planar defects and metal oxide nanoparticles on the surface of perovskite, which occurs under the reaction conditions was shown. Also formation of alternating perovskite – brownmillerite layers in reaction condition was shown by HRTEM data.