Optical studies in gamma-irradiated commercial soda-lime silicate glasses

Optical absorption measurements of gamma-irradiated (60Co) commercial soda-lime silicate (SLS) glasses were performed at room temperature (RT) to detect and characterize the induced radiation damage in these materials. Isothermal bleaching (RT-723 K) of the radiation-induced defects, followed the irradiation of samples. In glasses containing different amount of the glass-network modifiers (Na2O, K2O) and some multivalent transition metal cations (Fe2+/Fe3+, Ni2+ and/or Mn2+) three absorption bands have been distinguished in the wavelength region extending from 250 to 1800 nm. In contrast to the electron-type color centers, detected at low temperatures for X-irradiated nominally pure sodium silicates , we propose that the absorption bands found for gamma-irradiated SLS glasses are induced by some hole-type color centers related with nonbridging oxygen ions (NBO-) located in different surroundings. The radiation-induced enhancement of diffusivity of ions together with bond breaking and defect creation in the glass-network could give materials with well-defined nonlinear optical properties