مشخصات پژوهش

The present study investigates the compositional and structural effects of gamma irradiated graphene oxide (GO). Gamma irradiation doses of 20, 50, 70 and 90 kGy are used to treat GO in an air environment. The compositional, structural and nonlinear optical properties of the irradiated samples are studied using Fouriertransform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), photoluminescence, ultraviolet–visible (UV–Vis) spectroscopy, field emission scanning electron microscopy (FE-SEM), Thermogravimetric analysis (TGA), Raman spectroscopy and the Z-scan technique. XRD analysis confirmed the exfoliation of GO under gamma irradiation, while FT-IR and TGA results showed only small variations. Raman spectroscopy indicates that defect creation competes with graphitization in GO, depending on the absorbed dose. Results of FE-SEM analysis for irradiation doses in the range of 0–90 kGy indicate that GO edges are bent and shrunk. The nonlinear responses of un-irradiated and four-dose gamma irradiated samples are measured using the Z-scan technique. The n2 values are measured to be in the range of 􀀀 3.97 to 􀀀 8.86 × 10􀀀 10 cm2/W, indicating a selfdefocusing effect. Results indicated that gamma irradiation can be an effective way for changing the nonlinear optical responses.