Optimization,structural, optical and magnetic properties of TiO2/CoFe2O4 nanocomposites

Magneto-optical TiO₂/xCoFe₂O₄ nanocomposites having various concentrations of CoFe₂O₄ (x = 2, 4 and 6 wt %) were prepared using facile mechanical mixing. X-ray diffraction was employed for the phase examination and microstructure parameters. X-ray diffraction spectra proved the formation of two separate phases: tetragonal titanium dioxide (TiO₂) and face-centered cubic cobalt iron oxide. The structure was further verified by recognizing the selected area electron diffraction (SAED) pattern recorded by a high-resolution transmission microscope. The optical investigation of the prepared nanocomposites verified that the optical band gap values varied from 3.1 eV for pure TiO₂ to 3.05 eV for TiO₂/CoFe₂O₄ (6 wt %). The refractive index, optical dielectric constant and loss factor were discussed in detail. The nanocomposites (TiO₂/xCoFe₂O₄) demonstrated ferromagnetic characteristics and their magnetic parameters were affected by the CoFe₂O₄ percentage in the composites. The sample x = 2 wt % depicted the maximum magnetic exchange bias at room temperature. Moreover, it showed maximum coercivity (H_C) and magnetic squareness ratio (SQ), which makes it suitable for spintronic applications.