Investigation of Structural, Morphological and Optical Properties of Ni-Doped ZnFe₂O₄ Nanoparticles Synthesized by Sol-Gel Auto-Combustion Method

In this study, Ni_xZn_{1 – x}Fe₂O₄ (where x = 0.0, 0.03, and 0.06) nanoparticles were prepared using a sol-gel auto-combustion process. The study aimed to explore how the inclusion of nickel (Ni) affects the structural, morphological, vibrational, and optical properties of ZnFe₂O₄ ferrite nanoparticles. Various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and UV-Vis spectroscopy, were employed to investigate these characteristics. The XRD patterns of the synthesized samples confirmed the formation of a single crystalline phase without impurity phases. The analysis revealed that the average crystalline size, lattice parameter, and strain were found in the ranges of 33.03–37.38 nm, 8.331–8.310 Å, and 2.8007–2.4673, respectively. SEM analysis further supported the formation of nanoparticles, showing a spherical shape with a dispersed distribution and minimal agglomeration. Raman spectroscopy indicated that ZnFe₂O₄ ferrite nanoparticles doped with 6% Ni exhibited stronger and sharper peak intensity and bands compared to those doped with 0 and 3% Ni. Additionally, the energy band gap decreased from 5.42 to 1.24 eV with an increase in Ni concentration, in comparison to pure ZnFe₂O₄ ferrite nanoparticles. The study suggests that due to their exceptional characteristics and narrow band gaps, Ni-doped ZnFe₂O₄ ferrite nanoparticles hold promise for use in electronic device applications.