Thermal, optical, and gamma-ray shielding properties of CdO - PbO - Bi2O3 glasses

Abstract

Glass systems of a chemical composition of xCdO-(100−x)[50PbO - 50Bi₂O₃] (40 mol% ≤ x ≤ 80 mol%) were fabricated by melt-quenching method. The study examined how these glasses performed as shielding materials, based on their CdO content. The corresponding linear attenuation coefficient (LAC) values for the samples containing 40, 60, 70, and 80 mol.% of CdO are 678.953 cm⁻¹, 537.713 cm⁻¹, 441.381 cm⁻¹, and 372.764 cm⁻¹, respectively. The sample containing 40 mol.% of CdO exhibited the highest values of linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), and effective atomic number (Z_eff). Therefore, this sample is predominated for radiation protection. The mean free path (MFP) are 0.001, 0.002, 0.002, 0.003 cm at 0.015 MeV and 2.635, 3.068, 3.509, and 3.793 cm at 15 MeV, for the samples containing 40, 60, 70, and 80 mol.% of CdO, respectively. The differential scanning calorimetry (DSC) showed an endothermic (down) peak at a range of temperatures from 450 °C to 485 °C, related to the glass transition (T_g). The average refractive index (n_average), determined by some theoretical models, exhibits values ranging from 2.63 eV to 3.08 eV when determined using the E_g(direct). The values of the energy gaps of the studied glasses decreased by increasing the content of CdO (mol.%) due to the gradual rise in the quantity of non-bridging oxygen as the CdO content (mol.%) increases. The enhancement in optical basicity (Λ) by increasing CdO content (mol.%) in the studied glasses is strongly associated with a reduction in the strength of the metal-oxide bond. The values of the zero-frequency dielectric constant of the lattice (ε_L) are 1.13, 1.19, 1.52, and 1.62 corresponding to the samples containing 40, 60, 70, and 80 mol.% of CdO, respectively.