Local structure and cation distribution analysis of Mn1-xZnxFe2O4 powders by X-ray Absorption Near Edge Structure spectroscopy

Abstract In this work, Mn1-xZnxFe2O4 powders (x = 0.0, 0.2, 0.4, 0.6 and 0.8) were prepared by a conventional solid-state reaction method. The phase formation, local structure and cation distribution of Mn1-xZnxFe2O4 ferrite samples were investigated by X-ray Diffraction (XRD) and X-ray Absorption Near Edge Structure (XANES) Spectroscopy techniques. XRD analysis reveals that the single cubic spinel phase was formed in all prepared samples. The average crystallite size decreases with increasing zinc concentration. XANES measurements showed that the oxidation states of Fe and Zn ions in doped samples are +3 and + 2, respectively. The feature of the measured Fe, Mn and Zn K-edges XANES spectra are compared with the simulated XANES spectra obtained by using linear combination of the proportion of the distribution of Fe, Mn and Zn ions within the spinel structure. It is shown that a satisfactory agreement for the XANES Fe, Mn and Zn K-edges of Mn1-xZnxFe2O4 powders can be obtained introducing a mixed spinel structure with the majority of Fe3+ ions occupying tetrahedral sites and the majority of Zn2+ ions occupying octahedral sites. While, Mn2+ and Mn3+ ions were found to occupy both tetrahedral and octahedral sites with a higher stronger preference to be at the tetrahedral sites.