Effect of doping Mn ion on the crystal structure and cation distribution in Co1-xMnxFe2O4 compounds

Abstract

In this study, we investigated the effect of Mn doping on the crystal structure and the distribution of cations at tetrahedral and octahedral sites in Co_1-xMn_xFe₂O₄ compounds (0 ≤ x ≤ 0.4), synthesized utilizing a solid phase reaction method, utilizing X-ray diffraction (XRD) and Raman spectroscopy measurements. The surface morphology and chemical composition of the compounds were studied using scanning electron microscope and X-ray energy dispersive spectroscopy. The Rietveld refinement of XRD data using the Fullprof package demonstrate that all studied samples are single phase spinels with no other detectable phases and have a cubic structure with the space group of Fd-3 m. The lattice constant and unit-cell volume increased with increased Mn doping concentration, which are attributed to the larger ionic radius of Mn in comparison with Co. Both the X-ray diffraction and Raman spectroscopy results demonstrated that doping Mn at the Co-site leads to the movement of Fe cations from the tetrahedral sites to the octahedral ones.