Optical Properties Changes of Ternary Glasses: Gamma Irradiation Effect

Research on tellurite based glass has become important because of it potential in photonic and shielding material. In this work, the changes of the optical properties of ternary tellurite glasses when radiated with 25kGy gamma ray dose were studied. Five glass samples, with composition [(TeO2)70 (B2O3)30]100-x (Bi2O3)x (where x = 5, 10, 15, 20 and 25 mol%) were prepared by melt quenching technique. The optical properties were studied by UV-Visible absorption. The X-Ray Diffraction (XRD) spectra result shows that all glass samples fit the amorphous state. The Fourier Transform Infrared Spectroscopy (FTIR) was used to explore the structural bonding in the prepared glass samples due to exposure. Gamma irradiation causes a profound change in the peak intensity as shown by FTIR spectra which is due to the breaking of the network bonding. Before gamma irradiation, the optical band gap, Eg value decreased from 2.50 eV to 2.30 eV with the addition of Bismuth content. The value kept decreasing (from 2.18 eV to 2.05 eV) following exposure to 25 kGy gamma irradiation due to the increase of non-bridging oxygen (NBO) and the increase of defect in the glass. The finding suggest that the glass with high content of Bi2O3 (25 Bi) give smallest Eg and show less changes (less defect) in FTIR spectra after gamma irradiation which indicate that this glass is more resistant to 25 kGy gamma irradiation dose compared to other glasses.