Investigation of iron deficient and manganese doped Ni–Mg nano-ferroxide ceramics

Mn substituted ferrite series Ni0.5−xMnxMg0.5Fe1.98O4 with x=0.0, 0.1, 0.2, 0.3, 0.4 were prepared by a coprecipitation method. Samples were sintered at 600 °C for 3 h in a muffle furnace. Ferrite ceramics so obtained were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and Vibrating Sample Magnetometer (VSM) for their structural, morphological, optical and magnetic properties. XRD results confirmed cubic spinel structure with an average crystallite size in the range 33–47 nm. FTIR spectra showed the two main absorption bands in the range 400–600 cm−1 arising due to tetrahedral and octahedral stretching vibrations. Saturation magnetization increases with Mn2+ ion content, attains a maximum value of 35.7 emu/g at x=0.2 and then decreases. This can be attributed to super exchange interactions between cations in the spinel- lattice upon Mn substitution.