Exploring structural, morphological, and magnetic properties of CoFe2O4 nanoparticles: From sol-gel synthesis to theoretical insights

Cobalt ferrite is a spinel ferrite widely recognized for its excellent magnetic properties, chemical stability, and potential applications in magnetic, catalytic, and optoelectronic fields. In this work, CoFe 2 O 4 nanoparticles were successfully synthesized via a sol–gel method and systematically investigated using a combined experimental and theoretical approach. X-ray diffraction (XRD) analysis confirms the formation of a single-phase cubic spinel structure with an average crystallite size of approximately 36.96 nm. Scanning electron microscopy (SEM) reveals agglomerated nanocrystallites, while energy-dispersive X-ray spectroscopy (EDS) confirms the expected Co/Fe/O stoichiometry. Magnetic measurements indicate typical ferrimagnetic behavior, with a saturation magnetization of 53 emu/g and a coercivity of 1500 Oe. UV–visible spectroscopy shows strong absorption in the visible region, and the optical band gap, determined via Tauc plot analysis, is approximately 1.34 eV. To further elucidate the electronic structure, density functional theory (DFT) calculations were performed using the GGA+mBJ approach, revealing an indirect band gap of 2.54 eV along with significant hybridization among Co-3d, Fe-3d, and O-2p orbitals. The novelty of this work lies in this integrated experimental–theoretical investigation, which provides a comprehensive understanding of the relationship between the structural, magnetic, and optical properties of CoFe 2 O 4 nanoparticles. This approach offers valuable insights for the design and optimization of ferrite-based materials for advanced technological applications.