Enhanced nonlinear optical properties of GO and Fe₃O₄-Modified CuMn₂O₄ nanocomposites

The present study aims to investigate the optical and structural characteristics of CuMn₂O₄GO and CuMn₂O₄GOFe₃O₄ nanocomposites in comparison to CuMn₂O₄ nanoparticles, with the goal of exploring linear, nonlinear, and photonic applications. X-ray diffraction (XRD) analysis determined the crystallite sizes for CuMn₂O₄, CuMn₂O₄GO, and CuMn₂O₄GOFe₃O₄ samples synthesized by the co-precipitation method to be 16.31, 4.76, and 11.86 nm, respectively. SEM images demonstrate that the particles were generally well-dispersed and mostly spherical to hexagonal in shape. By analyzing the reflectance data through the Tauc model, the direct band gap energies were found to be 2.06 eV, 2.08 eV, and 2.18 eV for CuMn₂O₄, CuMn₂O₄GO, and CuMn₂O₄GOFe₃O₄ samples, respectively. To examine the NLO properties of the nanopowders, the Z-scan method was utilized with a 532 nm Nd: YAG laser at incident powers of [Formula: see text] = 20, 25, and 30 mW. The nonlinear absorption coefficient and refractive index determined by the Z-scan method were approximately (10³) and (10⁹), respectively. At [Formula: see text] = 30 mW, for CuMn₂O₄, CuMn₂O₄GO, and CuMn₂O₄GOFe₃O₄, the NLR and NLA reverse saturable absorption reactions are observed at 3.04 × 10^-9, 3.98 × 10^-9, and 10.3 × 10^-9 m²/W, and 8.6 × 10^-3, 6.4 × 10^-3, and 5 × 10^-3 m/W, respectively. The exceptional nonlinear optical (NLO) coefficients of the prepared nanopowders emphasize their potential for creating ultrafast lasers, anti-laser optical limiters, and two-photon microscopy.