A comparative study of nanosized iron oxide particles; magnetite (Fe3O4), maghemite (γ-Fe2O3) and hematite (α-Fe2O3), using ferromagnetic resonance

► Magnetic difference between single domain size iron oxides was investigated. ► Interparticle and intraparticle interaction in iron oxides were analyzed. ► The different intra interactions of same cations effect on resonance line asymmetry. ► Landé g values were obtained from the fit of resonant lines. ► The couplings of Fe2+ and Fe3+ ions by the mediation of O− ions were shown.