The Impact of Ni Substitution on the Structural and Magnetic Properties of Mg Nano-Ferrite

Magnesium substituted nickel nano-ferrite Mg_1−xNi_xFe₂O₄ (x = 0.0, 0.1, 0.3, 0.5, 0.7, and 1.0) was synthesized by the citrate-gel auto-combustion method. Synthesized powders were sintered at 600 ^∘C for 4 hours and characterized by X-ray, High Transmission Electron Microscopy, Brunauer-Emmett-Teller, Atomic Force Microscopy and Energy Dispersive X-ray Spectroscopy analyses. The impact of replacing Mg ions by Ni on the structural parameters and magnetic properties of the system was investigated utilizing X-ray diffraction and χ–T magnetic measurements at room and low temperatures. The crystallite sizes were found in the range of 24.6 nm – 27.6 nm. The variation of lattice parameter, the roughness, surface area and the porosity size upon increasing the Ni content were determined and then correlated with the cation distribution and the magnetic behavior. The coercivity (H_c) values vary from 56.4 Oe to 130 Oe. These values make the investigated samples well suited for their use in recording media. Magnetic parameters such as saturation magnetization, and Curie temperature (T_c) assured the existence of a critical concentration at x = 0.3 in which the anomalous character appeared.