TeO2-ZnO Glasses Incorporating Li2O, Na2O, TiO2, MoO3, And BaO for Optimization In Radiation Shielding

Abstract

This dissertation focuses on the development and characterization of tellurite glasses with enhanced radiation shielding capabilities, with the aim of providing efficient materials for protection against ionizing radiation. The glasses were studied in a ternary system to optimize their structural, thermal, optical, and shielding properties. XRD confirmed the amorphous nature of the samples, while scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) demonstrated homogeneous surfaces and a uniform chemical composition. Raman and FTIR spectroscopic analyzes identified key structural units, highlighting the influence of modifiers such as TiO2 and MoO3. These oxides were

shown to increase non-bridging oxygen (NBO) concentrations, improve structural arrange- ment, and enhance radiation absorption. The density and oxygen packing density (OPD)

analyzes revealed significant changes with the introduction of modifiers. BaO notably increased density and improved structural stability, while Na2O reduced compactness, resulting in a less cohesive network. Differential scanning calorimetry (DSC) indicated

that TiO2 and BaO enhanced thermal stability, increasing the glass transition tempera- ture (Tg) and the crystallization onset temperature (Tx). In contrast, Na2O showed lower

thermal stability. UV-Vis spectroscopy confirmed the glasses high efficiency in absorbing UV and visible radiation. The calculated optical band gap (2.18–3.74 eV) and Urbach energy provided information on the electronic structure, revealing the role of modifiers

in the tuning of optical properties. Mechanical characterization through Vickers hard- ness tests demonstrated superior mechanical strength in glasses modified with TiO2 and

reduced hardness with Na2O, correlating with the observed structural compactness. Op- tical microscopy corroborated the homogeneity of the materials, confirming the absence

of structural defects. Radiation shielding studies showed that the incorporation of BaO and MoO3 significantly improved gamma and neutron attenuation. BaO increased density and cross-linking, optimizing gamma radiation absorption, particularly at lower photon energies. MoO3 improved fast neutron shielding due to its higher density and structural rearrangement induced by molybdenum oxides. The mass attenuation coefficients (MAC) demonstrated that the tellurite glasses surpassed conventional shielding materials, such as lead and barite concrete, particularly at low photon energies. Half-value layer (HVL) measurements further underscored their effectiveness, achieving substantial protection with thinner layers, advantageous for lightweight and transparent shielding applications.

These findings highlight the versatility of tellurite glasses as advanced materials for ra- diological environments, offering a combination of transparency, mechanical robustness,

and superior radiation attenuation for various technological and industrial applications.