Mg1-xZnxFe2O4 nanoparticles: Interplay between cation distribution and magnetic properties

Correlation between cationic distribution, magnetic properties of Mg1-xZnxFe2O4 (0.0 <= x <= 1.0) ferrite is demonstrated, hardly shown in literature. X-ray diffraction (XRD) confirms the formation of cubic spinel nano ferrites with grain diameter between 40.8 to 55.4 nm. Energy dispersive spectroscopy (EDS) confirms close agreement of Mg/Fe, Zn/Fe molar ratio, presence of all elements (Mg, Zn, Fe, O), formation of estimated ferrite composition. Zn addition (for Mg) shows: i) linear increase of lattice parameter a(exp), accounted for replacement of an ion with higher ionic radius (Zn > Mg); ii) presence of higher population of Fe3+ ions on B site, and unusual occurrence of Zn, Mg on A and B site leads to non-equilibrium cation distribution where we observe inverse to mixed structure, and is in contrast to reported literature where inverse to normal transition is reported; iii) effect on A-A, A-B, B-B exchange interactions, affecting coercivity H-c, M-s. A new empirical relation is also obtained showing linear relation between saturation magnetization M-s - inversion parameter delta, oxygen parameter u((43) over tildem). Non-zero Y-K angle (alpha(YK)) values implies Y-K type magnetic ordering in the studied samples. (c) 2017 Author(s).