Effect of gamma rays on magnetic and linear/nonlinear optical properties of pristine and modified nickel ferrite nanoparticles

In this study, pure and surfactant-added nickel ferrite nanoparticles are successfully synthesized using the co-precipitation method. The prepared samples are investigated before and after irradiation of gamma ray and compared. The linear and nonlinear optical responses, morphological, magnetic, and structural properties are examined using the photoluminescence, ultraviolet-visible spectroscopy, z-scan technique, field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), vibrating-sample magnetometer (VSM), and Raman spectroscopy analysis. The XRD analyses of the samples showed their crystallinity with no significant change after gamma irradiation. The grain sizes of the irradiated and surfactant-added nickel ferrites are decreased. According to the FE-SEM images, the synthesized particles are spherical. Based on the VSM results, the nanoparticles displayed superparamagnetic properties. However, after gamma irradiation and adding the surfactant, the magnetic saturation is reduced. The band gap of unmodified samples is measured in the range of 2.05-3.92 eV before and after gamma irradiation. Moreover, the band gap of the nickel ferrite samples modified with cetyltrimethylammonium bromide-tartaric acid is in the range of 2.07-3.84 eV. The closed- and open-aperture z-scans are used to measure the nonlinear refractive index and absorption coefficient, respectively. Based on analysis and data, our synthesized nanoparticles can be a good candidate for various applications such as hyperthermia, catalysis, and optical switches.