Structural studies and magnetic evaluation of Ni-Mg-Co nanoparticle ferrites synthesized by sol–gel method

Ni-Mg-Co Ferrite nanoparticles with chemical formula Ni_0.6-xMg_xCo_0.4Fe₂O₄ were prepared by standard sol–gel auto ignition technique. The phase purity and structural formation was confirmed through the analysis of X-ray diffraction technique. The results of X-ray diffraction analysis show the single phase cubic spinel nanocrystalline structure. SEM and TEM images show that the particles have spherical shape with particle size in the range of 40 to 60 nm and consistent with XRD result. The EDX analysis exhibits the ratio of constituent elements almost appears in the final product. The vibration properties of nanoparticles are analysed by FT-IR spectrum. The FTIR spectroscopy results confirm the spinel structure formation through the characteristic bond vibrations of cations in tetrahedral (around 600 cm⁻¹) and octahedral (near 400 cm⁻¹) sites. The results reveal that the saturation magnetization, remnant and coercivity decrease due to the presence of Mg²⁺ cation instead of a part of Ni²⁺. The magnetic properties of these nanoparticles are studied for confirming the ferromagnetic behaviour at room temperature. The obtained properties make the Ni-Mg-Co ferrites suitable for high frequency purposes, electronic devices, transformers, and low-dissipation magnetic storage.