Nuclear radiation shielding characteristics and physical, optical, mechanical, and thermal properties of lithium-borotellurite glass doped with Rb2O

Abstract The current paper addresses the influence of Rb2O in the lithium-borotellurite (LBT) glass system for the first time. For this, the glass system (25-x)Li2O–15B2O3–60TeO2-xRb2O was designed where x: 0, 5, 10, 15, 20, and 25 mol%. An extensive investigation was carried out to understand the alterations in physical, optical, thermal, and mechanical properties with the use of theoretical calculations. The user-friendly Phy-X/PSD software was employed to demonstrate the nuclear radiation protection properties. From physical property calculations, the addition of Rb2O from 0 to 25 mol% increased average molecular weight (AMW) from 113.68 to 152.94 g mol−1 and glass density (ρglass) from 4.2743 to 4.7710 g cm−3. Likewise, molar volume (Vm), oxygen molar volume (VO), oxygen packing density (OPD), and number of bonds per unit volume (nb) were considerably changed by the increasing Rb2O concentration. According to the optical calculations, the refractive index (n) increased from 2.3348 to 2.6104, while the dielectric constant (e) increased from 5.45 to 6.81. Moreover, the metallization criterion (M) showed a decreasing trend, and implied increasing insulation with the increase in Rb2O in the glass system. For thermal property estimations, viscosity versus temperature profiles clearly indicated that all R-series have the ability to form glass, but decreasing the Li2O caused an increment in glass melting temperature. The mechanical moduli determinations via the Mackenzi-Makishima model demonstrated that Young's (E), bulk (B), shear (S), and longitudinal (L) moduli were gradually decreased by introducing Rb2O into the glass network. From the perspective of radiation shielding calculations, the essential parameter, linear attenuation coefficient (LAC), effectively improved by increasing the doping rate of Rb2O. Based upon the LAC values, the other critical parameters such as mean free path (MFP), half-value layer (HVL), and effective atomic number (Zeff) were successfully evaluated. Additionally, build-up factors such as exposure (EBF) and energy absorption (EABF) were assessed with the implementation of G-P progression. They showed that sample-R25 ensured better gamma-ray shielding properties compared to the other samples. Lastly, fast neutron removal cross-section (FNRCS) determinations displayed decreasing behaviour with the increasing Rb2O content, which is not convenient for effective neutron shielding abilities. All in all, the Rb2O-reinforced borotellurite glass can serve as an alternative radiation shielding material.