Structural and magnetic studies of NiMn0.05TixMgxFe1.95−2xO4 ferrite

The present work is carried out to investigate the effect of co-substitution of non-magnetic ions, Mg+2 and Ti+4, at Fe site in a basic nickel ferrite. The single-phase formation of the materials was confirmed by XRD analysis. The effective modifications in the exchange interactions were observed from structural, magnetic and Mössbauer studies. The substitution of the two ions, Mg2+ and Ti4+, at Fe site reduces the saturation magnetization, Néel temperature (TN) and initial permeability (μi) with increasing concentration of substituents. The observed variations in different properties were discussed on the basis of the site occupancy of the metal ions in the crystal structures. 57Fe Mössbauer studies reveal the reduction in magnetic moment on substitution. The relaxation is observed for the higher substitution level (x≥0.4) evident from the Mössbauer studies. The doublet along with the two sextet is observed in the Mössbauer spectra which is found to increase with the increased level of substituents and explained on the basis of domain wall oscillation and displacement model.