Cation Distribution in the Composite Materials of the CaFe2O4--Fe2O3 Series

Structured composite materials CaFe₂O₄-α-Fe₂O₃ (α-Fe₂O₃ content is 2–82 wt.%) are obtained with the method of solid-phase synthesis at 1000 °C. The phase composition of the samples is studied using powder X-ray diffraction. It is shown that the content of CaFe₂O₄ and α-Fe₂O₃ phases changes linearly, depending on the composition of the starting material. The scanning electron microscopy data indicate the formation of a two-phase system α-Fe₂O₃-CaFe₂O₄. The Mössbauer spectroscopy data at room temperature testify the formation of cationic iron vacancies in the CaFe₂O₄ crystal structure in the absence of α-Fe₂O₃ structural defects. Cationic vacancies can be formed during the synthesis in the atmosphere of air.