Study of structural, electrical and magnetic properties of co-substituted Co_1−2xNi_xMg_xFe₂O₄ (0 ≤ x ≤ 0.25) nanoferrite materials

In this study, we addressed the synthesis of spinel-structured nano-scaled materials involving Ni²⁺ and Mg²⁺ substitutions in (Ni_xMg_xCo_1−2xFe₂O₄ with 0 ≤ x ≤ 0.25) through the citric acid-catalyzed sol–gel combustion method. The investigation was motivated by the need to understand the synthesized materials' structural, electrical, and magnetic properties. We identified the problem of the non-uniformly shaped grains and their varying sizes, impacting the overall structure. Our method involved powder X-ray diffraction (XRD) for structural studies, revealing the formation of pure single-phased nanoparticles. The unit cell parameters fell within the range of 8.3782–8.4325 Å, validating the successful synthesis. Morphological analysis further uncovered randomly distributed, non-uniformly shaped grains with varying sizes, influencing the electrical and magnetic properties. Fourier transform infrared spectroscopy (FTIR) confirmed the spinel structure synthesis. The DC electrical resistivity, dielectric, and AC measurements displayed a non-monotonic pattern concerning dopant concentration, highlighting the complexity of the electrical behavior. Dielectric measurements suggested lower frequency dispersion effects attributed to high polarization at grain boundaries. Room temperature magnetic measurements, conducted using a vibrating sample magnetometer (VSM), demonstrated tuned variations in magnetic parameters. In conclusion, our comprehensive analysis provides valuable insights into the synthesis, structure, and properties of spinel-structured materials, contributing to understanding their potential applications.