Optical absorption and track studies of gamma-irradiated ZnP glass

The optical absorption spectra of a specially prepared zinc phosphate glass (ZnP) were studied as a function of gamma dose. The optical absorption spectra in the wavelength region of 200–800 nm were recorded for pristine ZnP glass sample and a number of samples exposed to different γ-doses in the range 10⁰–10⁶ Gy. The optical energy gap (E_g) was determined using Tauc's plot. It was found to be independent of γ-irradiation up to the dose of 10³ Gy followed by a slow decrease of E_g up to 10⁵ Gy. However, a sharp decrease in optical energy band gap was observed at 10⁶ Gy. The bulk-etch rates for different γ-doses were also determined and found to be constant up to the dose of 10⁵ Gy. On the other hand, there is a 12% increase in the bulk-etch rate for the dose of 10⁶ Gy.