New type of intrinsic color centers in sodium - silicate glasses

The absorption spectra of intrinsic color centers (CC) in sodium-silicate glasses in the 2-3 eV range have been investigated. The glasses of 22Na2O, 3CaO, 75SiO2 composition with variable content of iron from 5x10-5 to 3.5x10-2 mas.% have been studied. CC in glasses are formed as a result of UV effect or γ-radiation (dose rates - 105-108 R) at room temperature. The absorption band with maximum of 2.4 eV is detected in the absorption spectra occurring in sodium-silicate glasses under ionizing radiation. This band belongs intrinsic hole color centers of a new type. Detection of its spectrometric parameters permirs essentially to refine the parameters of the early known bands with maxima from 2.0 to 2.8 eV region. The position of band maxima forming absorption spectra of color centers in the region from 2 to 3 eV and their half-widths constitute 2.0, 2.4, 2.85 and 0.40, 0.45, 0.7 eV correspondingly. The error of description of the absorption spectra of color centers in the region from 2 to 3 eV by the Gauss contour with the given parameters doesn't exceed measurement errors (∼1%)