Effect of Ni2+ and Fe3+ Ion Concentrations on Structural, Optical, Magnetic, and Impedance Response of NiFe2O4 Nanoparticles Prepared by Sol-Gel Process

Abstract

In this study, NiFe2O4 (1:1, 1:2, 1:3, 2:1, and 3:1) nanoparticles were synthesized via sol-gel method and thermally treated at 900 °C. The reflection planes with single and two phases by homogeneous and nonhomogeneous distributions of Ni2+ and Fe3+ ions in cubic spinel nickel ferrite samples confirmed by using XRD patterns through the Rietveld refinement method and FTIR analysis. The changes in structural parameters correlated with the morphology and elements obtained from FESEM and EDS analysis. UV-vis diffuse reflectance spectra images indicate that the band gap ranges from 1.87 to 1.57 eV by varying the ratios of precursors. The homogeneity of Ni2+ and Fe3+ ions between the octahedral and tetrahedral sites plays a desired role in the magnetic and impedance responses. Maximum saturation magnetization of 66.26 emu/g with pure ferromagnetic behavior and high impedance response of 1.15 × 105 Ω were obtained, and then the value decreased due to the nonhomogeneous distribution.