Effects of magnesia addition on structural, morphological and magnetic properties of nano-crystalline nickel ferrite system

Nano-crystalline magnesia doped nickel ferrite powders have been synthesized by the combustion route. The structural, morphological and magnetic properties of the products were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy and vibrating sample magnetometer (VSM). X-ray analysis showed that all samples were cubic spinel. The increase in magnesia concentration resulted in a decrease in the average crystallite size, lattice constant, unit cell volume, X-ray density, ionic radii, the distance between the magnetic ions and bond lengths on tetrahedral sites and octahedral sites of the as prepared ferrite. The combustion method led to formation of spongy and fragile network structure. Increasing amounts of magnesia brought about remarkable changes in the microstructure and porosity of nickel ferrite. Doping of nickel ferrite by magnesia led to a decrease in its saturation magnetization. The minimum saturation magnetization value of nickel ferrite due to the doping 1 wt.% MgO attained 44.18 emu/g.