Effect of sintering temperature on cation distribution in CoFe2O4 nanoparticles

Abstract

We report a study of the cation arrangement in CoFe₂O₄ nanoparticles synthesized using a co-precipitation method followed by high-temperature sintering in the range of 500–1000 °C. Analysis of the samples by Raman, infrared, and X-ray photoelectron spectroscopy (Fe 2p_3/2 and Co 2p_3/2) revealed that the sintering temperature influences the distribution of cations in the spinel lattice. Specifically, increasing the sintering temperature leads to an increase in the inversion degree parameter (γ), which represents the fraction of Co ions residing in octahedral sites, driving the structure toward a fully inverted spinel. These results are in good agreement with those previously obtained by ⁵⁷Fe Mössbauer spectroscopy, X-ray diffraction, and X-ray absorption experiments on the same set of samples. Additionally, as shown by the UV–visible spectra, the cationic distribution in the samples clearly affects the band gap value (2.5–2.8 eV).