We report on the formation, crystal structure, and hyperfine interactions of Mn2+/ Zn2+ codoped Fe3O4 nanocrystalline particles using techniques such as XRD, TEM, Raman, and Mössbauer spectroscopies. Highly crystalline spinel-related Mn2+/Zn2+ codoped Fe3O4 nanoparticles with a composition of MnxZn0.2Fe3−yO4 ( \(\:y=\frac{2}{3}\left(x+0.2\right),\) x = 0.0, 0.1, 0.15, 0.2, 0.25, and 0.3) and an average size of ~ (17 ± 4) nm are synthesized by precipitation method as confirmed by the XRD and TEM. Raman spectroscopic data reveal that codoping with Mn2+ and Zn2+ suppresses the magnetite -to- maghemite phase transformation for the samples with x ≥ 0.2. Consistent with the Raman results, Mössbauer spectroscopic data show a decrease in the γ-Fe2O3 phase as x increases from about 12% for x = 0.0 to approximately 6% for x = 0.15 almost vanishing in samples with x ≥ 0.2. The changes in isomer shifts, quadrupole shifts, and hyperfine fields with increasing x values are discussed. The cationic distribution attained from Mössbauer data analysis indicates that both cations preferentially substitute for Fe3+ cations at the A-site. This preferential substitution is accompanied by interstitial cation substitution, which is required to preserve the overall cationic stoichiometry.
