Magnesium substituted nickel ferrite nanoparticles are prepared by using citrate precursor method. Synthesized nanoparticlesare analyzed by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy Dispersive X-ray (EDX) Analysis,Fourier transform infrared (FTIR) and Vibrating sample magnetometer (VSM). The crystalline size of nanoparticles isestimated to be 17-70 nm by using Debye Scherrer formula, Modified Scherrer formula and Williamson-Hall method. Twomain peaks near 570-590 cm−1 and 400-470 cm−1 confirm the spinel structure. Substitution of Mg2+ ion increases the saturationmagnetization value up to x = 0.4 after that decreases. Yafet- Kittel angle value increases with increasing Mg2+ concentration.

Keywords: Scherrer formula, lattice constant, bond length, Curie temperature, Yafet-Kittel angle, Tetrahedral