Impact of TiO₂-Doped Bismuth-Boro-Tellurite Glasses: Fabrication, Physical and Optical Properties, and γ-Ray Protection Competence for Optical and Radiation Shielding Applications

Bismuth-boro-tellurite glasses reinforced with TiO₂ with the chemical formula (58−X)B₂O₃ + 19.5TeO₂ + 0.5Nd₂O₃ + 12Bi₂O₃ + 10Li₂O + XTiO₂ (where X = 0 mol.% for the sample labeled NdTi0 to X = 10 mol.% for the sample labeled NdTi10, in steps of 2.5 mol.%) were investigated. Samples were prepared using the conventional melting and quenching technique. The impact of TiO₂ on the structural, optical, and physical characteristics and γ-ray protection competence of the NdTiX samples was investigated. The amorphous state of NdTiX samples was confirmed via x-ray diffraction (XRD) measurements. The density (D_s) increased from 3.52 g/cm³ to 3.90 g/cm³. The molar volume (V_m) declined from 37.49 cm³/mol to 34.15 cm³/mol. The ultraviolet (UV) absorbance spectra confirmed that ten essential peaks reflected the electronic transitions from the ground state (⁴I_9/2) of Nd³⁺ to higher states. The indirect optical energy gap (E_g) decreased from 3.59 eV for the NdTi0 sample to 3.18 eV for the NdTi10 sample. Urbach energy (E_U) values declined from 0.47 eV to 0.23 eV. The refractive index (n) increased from 2.25 to 2.35. Molar refractivity (R_m), reflection loss (R_L), and molar polarizability (α_m) were enhanced as TiO₂ content increased in the glass networks. The mass absorption coefficient (MAC) followed the order (NdTi0)_MAC < (NdTi02.5)_MAC < (NdTi05)_MAC < (NdTi07.5)_MAC < (NdTi010)_MAC. The half-value layer (HVL) followed the order (NdTi0)_HVL > (NdTi02.5)_HVL > (NdTi05)_HVL > (NdTi07.5)_HVL > (NdTi010)_HVL. The Z_eff values followed the same order as the MAC, while the mean free path (MFP) followed the same order as the HVL. The obtained results showed that NdTiX samples can be used in optical and γ-ray shielding applications