The effect of different doses of γ -ray irradiation on the third order nonlinear optical properties, molecular structure and mass attenuation coefficients of synthesized colloidal silver nanoparticles

Silver nanoparticles (Ag NPs) stable colloid solution were prepared via Creighton method and successively irradiated with gamma rays from a Co-60 source at integral doses of 20 Gy, 200 Gy, 1 kGy and lOkGy. The size of obtained nanoparticles was determined by field emission scanning electron microscopy (FESEM) is about 30 nm. The structure of synthesized Ag NPs was characterized by UV-Vis spectroscopy and X-ray diffraction (XRD) techniques. A wide absorption band centered at 400 nm can be distinctly observed by UV-Vis spectroscopy. Bragg reflections in X-ray diffraction analysis confirmed the presence of face-centered cubic (fcc) Ag NPs. The third-order nonlinear optical properties, molecular structure and mass attenuation coefficients of nano colloidal silver were studied before and after gamma-ray irradiation. Prepared Ag NPs exhibit strong third-order nonlinear optical responses, which have been performed with a Z-scan technique using continues wave (CW) He: Ne laser emitting 632.8 nm. Comparing nonlinear results show that the magnitude of nonlinearity enhanced by increasing the dose of gamma -ray irradiation. Raman signals of the obtained Ag NPs are significantly enhanced after the gamma-irradiation process. Also, the experimental results using gamma spectroscopy method have shown that the mass attenuation coefficients of Ag NPs decrease after gamma irradiation. Briefly, results demonstrated that gamma-rey irradiation is an effective method for tailoring the properties of Ag NPs.