Ahmed H. Hammad

The phosphate (P2O5) network is a typical glass-forming system, similar to silicate (SiO2), borate (B2O3), and germanate (GeO2) glasses. The phosphate network’s physical and chemical properties are...

The research has examined the structure, elasticity, and various radiation shielding properties of a bismuth cadmium borate glass system containing samarium ions using empirical methods. The glass density ( D _glass ) was experimentally measured by Archimedes’ principles. When 4 mol% of samarium oxide (Sm ₂ O ₃ ) was introduced to the host glass, the density of the base (free Sm ₂ O ₃ ) sample dropped from 5.597 g cm ⁻³ to 5.468 g cm ⁻³ . The Makishima-Mackenzie (M–M) model was used to compute the elastic parameters, including Young’s ( E ), shear ( S ), and bulk ( B ) moduli. These parameters increased from 37.009 to 38.003 GPa, from 14.908 to 15.317 GPa, and from 23.827 to 24.410 GPa, respectively. Exposing the base sample to 8.04 keV yielded a mass attenuation coefficient ( MAC ) of 178.048 cm ² g ⁻¹ . Adding 4 mol% Sm ₂ O ₃ to glass increased its MAC to 188.797 cm ² g ⁻¹ . If the glass thickness is increased to 3 cm, the high radiation energy of 2.506 MeV can be reduced to half its value ( HVL ). The effective atomic number ( Z _eff ) for the base sample at 19.63 keV was 77.957, decreasing to 27.071 at 661.7 keV. A similar trend was observed for all other glass samples. Such calculations reveal a promise in radiation shielding protection.

The objective of the current study is to assess the structural , optical filter property, and photoluminescence of a glass system primarily made of barium phosphate doped with vanadium pentoxide (V₂O₅), in which the structural units of phosphate (P₂O₅) are replaced by tellurium oxide (TeO₂). The phosphate network consists of PO₄ units in Q² and Q³ modes, while TeO₂ exists as trigonal pyramid TeO₃ units. Density decreased from 3.263 to 3.046 g cm⁻³ with TeO₂ addition up to 15%, then increased to 3.486 g cm⁻³ at 20% TeO₂. Depending on the TeO₂ concentration, the addition of TeO₂ to the glass network produces a region with zero transmittance that extends from 672 nm to 998 nm. Furthermore, a cut-off wavelength in the visible and near-infrared (NIR) range was observed in every glass sample. The visible and near-infrared (NIR) cut-off wavelengths of the glass containing 5 mol% TeO₂ are 510 nm and 998 nm, respectively. The cut-off wavelengths of the other samples were lower than those of the 5% TeO₂ sample. The optical band gap rose from 2.08 to 2.166 eV as the TeO₂ content increased from 5 to 20 mol%, while the refractive index dropped from 2.703 to 2.668, respectively. The color purity (CP%) of the glasses is enhanced by the intercalation of TeO₂ into the barium phosphate network. The base sample presented a color purity of 19%, which increased to 71% and 82% with a TeO₂ contribution of 5 and 10 mol%. However, the color purity decreased to 38% at 20 mol% of TeO₂ due to the network former effect of TeO₂.

Invert zinc-barium phosphate (ZnO–BaO–P₂O₅) glass networks were fabricated using the melt-annealing technique. The base glass was modified with cadmium oxide (CdO), lead oxide (PbO), and a mix between CdO and PbO. The elastic parameters were discussed using the Makishima-Mackenzie approach. The calculated values of Young’s (E), bulk (B), and shear (S) moduli decreased after the CdO, CdO+PbO, and PbO were introduced to the network from 53.704 to 52.019 GPa, 34.034 to 32.860 GPa, and 23.184 to 22.473 GPa, respectively. XCOM database was used to compute the mass attenuation coefficient (MAC) and estimate the radiation shielding properties of such glasses. For example, the MAC for the base sample at 0.06 MeV was 3.365 cm²/g, which rose to 3.554 cm²/g for the sample containing PbO. The mean free path (MFP), tenth value layer (TVL), and effective atomic number (Z _eff ) were all discussed. The MFP values depend on the glass composition, which decreased from 0.091 cm (the base sample) to 0.082 cm (the glass with PbO) at 0.06 MeV. The phosphate glass, which contains PbO and CdO+PbO, is more suitable for radiation shielding applications.