Spectroscopic study on the valence state of Fe in BiFeO3

Abstract

Bismuth ferrite is a hot spot in the research of multiferroic materials and its spectral research is of great significance to the research of mechanism, properties, and material characterization. The core electron excitation of Fe in BiFeO3 has been studied, and the spectra of Fe K-edge, L2,3-edge, and M-edge were calculated. Combining free-ion multiple theory and crystal field theory, the spectra were calculated to display the core electronic transition of Fe from the shape and peak of the spectrum and theoretically estimated the proportion of Fe3+ in BiFeO3. At L2,3-edge, the shape of the spectrum is mainly determined by the strong dipole transition of 2p→3d. Especially when the content of Fe3+ is 85% and Fe2+ is 15%, the spectrum calculated is in good agreement with the experimental spectrum, and this result is basically consistent with the proportion of 85%–88% in K-edge.