Cationic distribution assisted tuning of magnetic properties of Li_0.5-x/2Zn_xFe_2.5-x/2O₄

Zn addition induced modification of cationic distribution for tuning magnetic properties of Li_0.5-x/2Zn_xFe_2.5-x/2O₄ (x = 0, 0.1, 0.25, 0.3, 0.5, 0.7, 0.9, 1.0) powders is studied by x-ray diffraction (XRD) and magnetic measurements. XRD shows the formation of cubic spinel structure, with Scherrer's grain diameter ranging between 26.7 to 37.8 nm. With Zn addition, oxygen anions are displaced in such a way that the A-B interaction weakens, whereas A-A and B-B interaction strengthens; furthermore it also pushes Fe³⁺ and Li¹⁺ ions to B site, leading to changes in magnetic properties. Highest saturation magnetization (M_s) of 64.6 A m² / kg was obtained for sample with x = 0.25 and lowest coercivity (H_c) of 4949.9 A/m was obtained for the sample with x = 0.7. Calculated values of experimental magnetic moment 'n_B' and Neel magnetic moment 'n_N', display similar trend as that of M_s. Present results very clearly show a strong correlation between Zn-addition induced changes in cation distribution and magnetic properties, which can be utilized effectively for tuning magnetic properties.