Borotellurite Glasses for Gamma-Ray Shielding: An Exploration of Photon Attenuation Coefficients and Structural and Thermal Properties

Gamma-ray attenuation characteristics and vibrational and thermal features have been studied for singly doped erbium (Er), dysprosium (Dy), and Er/Dy-codoped sodium lithium zinc lead borotellurite glasses. For all glasses, the amorphous nature was confirmed from the x-ray diffraction profiles, and BO3, BO4, TeO4, TeO3+1, and TeO3 structural units were identified by both Fourier transform infrared spectroscopy and Raman spectroscopy. Glass transition (T-g), onset crystallization (T-x), peak crystallization (T-c), and melting (T-m) temperatures including thermal stabilities (T) were evaluated following the glass differential scanning calorimetry profiles. An enhancement in T-g (359399 degrees C) and T variation at 131-169 degrees C with Er2O3, Dy2O3, and Er2O3/Dy2O3 incorporation suggested that the prepared glasses possess good thermal stability. The radiation shielding properties within the 0.356-1.33-MeV photon energy range were assessed for all the glasses. The mass attenuation coefficient (/) values have been calculated using Monte Carlo simulation code. Further, photon interaction parameters like effective atomic number (Z(eff)), half-value layer (HVL), and mean free path (MFP) were also computed. The host and 1.0Er/1.0 Dy (mol.%)-codoped glasses possess the lowest and highest Z(eff) values and their magnitudes are varied within the range 11.40-15.99 and 12.14-17.26, respectively. For the host glass, exposure buildup factor values were calculated by the geometric progression (GP) fitting method within the 0.015-15-MeV energy range and up to a penetration depth of 40 MFP. The removal cross sections sigma(R) (cm(-1)) for fast neutrons were calculated to evaluate the attenuation of neutrons through the prepared glasses.