Papers by Author: N. Chanthima

Abstract: In this work, Na₂O-Al₂O₃-BaO-CaO-Sb₂O₃-B₂O₃-SiO₂ glasses doped with Er³⁺ was prepared and investigated for their physical, optical and visible luminescence properties. The increases in density, refractive index and molar volume of the glasses with additional doping content of Er₂O₃ into the network were due to a higher molecular weight and polarizability of Er₂O₃ in comparison with the glass former (SiO₂ and B₂O₃). Ten absorption peaks were observed as a nature of Er³⁺ absorption in glass matrices. The glass exhibited four emission transitions which were assigned to ⁴F_5/2→⁴I_15/2 (460 nm), ⁴F_7/2→⁴I_15/2 (487 nm), ²H_11/2→⁴I_15/2 (522 nm) and ⁴S_3/2→⁴I_15/2 (545 nm) transitions. The strongest intensity was the green emission at 522 nm. The luminescence intensity was found to increase with Er₂O₃ content up to 4 mol% and it was decreased for higher Er₂O₃ contents due to concentration quenching effect.

Abstract: Mass attenuation coefficient, total interaction cross-section and effective atomic number of xPbO:(100-x)SiO2, where 30 x 70 (% weight), glass system have been investigated at 662 keV on the basis of the mixture rule. The results are in good agreement with the theoretical values, calculated by WinXCom. The mass attenuation coefficient increases with PbO content, due to higher probability of photoelectric absorption in glass. However, Compton scattering gives dominant contribution to the total mass attenuation coefficient for the glass samples studied. The shielding properties of the glass samples are also better than ordinary shielding concretes and commercial window glasses. These results indicate that the glass systems prepared in this study has a potential to be used as radiation shielding materials.