Dixit, GaganJoshi, Lekha2019-09-042019-09-042019-08http://krishikosh.egranth.ac.in/handle/1/5810126218Swift heavy ions of various energies are being used for material modifications. The induced modifications depend on the kind of defects produced during interaction of ions with target material. In the present work, structural and optical properties of Oxygen irradiated NiFe1.96Ce0.04O4 have been studied. NiFe2O4 nanocrystals doped with 4% Cerium ions were synthesized by chemical route using nitrates of Fe, Ni and Ce with citric acid. The sample was irradiated at 1×1012 ions/cm2, 5×1012 ions/cm2, 1×1013 ions/cm2 and 2×1013 ions/cm2. SRIM calculation show that electronic energy loss is less than the threshold value for O beam, so point defects are expected in the system. Structural characterization were performed using XRD and FTIR Spectroscopy & optical properties were studied by UV-Vis spectroscopy in DRS mode. The cubic spinel structure of sample was confirmed by XRD and IR spectra. All the parameters estimated from XRD patterns, show changes only at the fluence of 5×1012 ions/cm2. UV-Vis spectra show two direct band gaps for all samples corresponding to both low and high spin electrons. Band gaps were found to be higher for sample irradiated at 2×1013 ions/cm2 fluence in comparison to that of pristine sample. It can be concluded that 100 MeV Oxygen irradiation enhances the optical band gap of Ce doped nickel ferrite nanoparticles without producing any structural distortion up to the fluence of 2×1013 ions/cm2.ennullThesis