We investigate the structural, spectral, and luminescent behavior of Eu3+-activated tellurite-borate glasses using various spectroscopic techniques, including UV-Vis-NIR absorption, photoluminescence (PL), and lifetime measurements. FTIR spectra identified structural units, such as [TeO4] and [BO4]. XRD analysis verified the amorphous character of the samples. The Judd-Ofelt (JO) analysis is employed to evaluate the radiative features, and quantum efficiency of the Eu3+ transitions, revealing enhanced red emission. The effects of Eu3+ content, glass composition on the emission intensity and decay time are systematically explored to optimize the material's performance for specific applications. Energy transfer processes, including Gd3+-Eu3+ interactions, are studied in detail, with evidence of non-radiative energy transfer (ET) leading to enhanced red emission at specific concentrations. CIE (Commission Internationale de l'Eclairage) chromaticity coordinates and correlated color temperature (CCT) is also evaluated, revealing tunable red orange light. The results demonstrate that Eu-doped tellurite-borate glasses exhibit appreciable luminescence efficiency and long emission lifetimes, making them suitable candidates for next-generation laser materials and display.
La2O3-Ta2O5-based Sm3+-scintillating glasses were successfully fabricated by the conventional melt-quenching technique for advanced X-ray computed tomography (XTM) applications. The effects of Sm2O3 concentration on the physical, structural, optical, luminescence, scintillation, and X-ray imaging properties of the prepared glasses were systematically investigated. The density and refractive index increased with increasing Sm2O3 concentration due to the incorporation of high atomic of Sm2O3 in glass matrix. FTIR and XPS analyses revealed structural modification of the silicoborate network with increasing NBO formation after Sm3+ incorporation. The glasses exhibited characteristic Sm3+ absorption and orange-red emission transitions corresponding to the 4G5/ 2 -> 6H7/2 transitions. The strongest emission was observed at 600 nm, and the optimum luminescence intensity was obtained at 1.5 mol% Sm2O3. The prepared 1.5Sm glass exhibited a high photoluminescence quantum yield of 28.18%. Under X-ray excitation, strong radioluminescence and millisecond-order scintillation decay behavior were observed. X-ray imaging experiments using synchrotron radiation demonstrated that the developed glass scintillator was capable of resolving microstructural details and producing reconstructed 3D images. While the prepared glasses exhibited lower spatial resolution and MTF values than commercial YAG scintillators, as well as lower scintillation efficiency than BGO single crystals, they were still capable of producing clear X-ray images with a spatial resolution of 79.86 LP/mm. The glasses demonstrated satisfactory imaging performance while offering several practical advantages, including straightforward fabrication, flexible composition, good optical transparency, and stable luminescence characteristics. These features indicate that the developed glass system has considerable potential for further optimization and application as a cost-effective X-ray imaging scintillator.
Eu3+-doped alkali calcium alumino phosphate oxide (OD) and oxyfluoride (OF) glasses were successfully fabricated using the conventional melt-quenching route. Comparative analyses were performed between the two systems to evaluate their physical, optical, photoluminescence and X-ray induced luminescence properties. The OD glass exhibited higher density and refractive index compared to the OF glass, indicating a more compact glass network. However, the molar volume of the OD was lower than that of the OF due to the larger free volume generated by fluoride incorporation. Based on the absorption spectra, both glass systems exhibited almost identical spectral profiles with minor variations in absorbance intensity. In the photoluminescence study, both glass systems exhibited strong red emission at around 612 nm (5D0 -> 7F2 transition) under 394 nm excitation. The OF glass exhibited a higher emission intensity than the OD glass, primarily due to the lower concentration of hydroxyl groups that act as non-radiative quenching centers. Both glass systems exhibited a reddish-orange emission, in good agreement with the CIE 1931 chromaticity coordinates. The X-ray-induced luminescence exhibited a spectral pattern comparable to that of photoluminescence, while differing in excitation source and luminescence mechanism. The integrated scintillation efficiencies of both glass systems were derived from the peak areas of their X-ray-induced luminescence spectra and compared with that of a Bi4Ge3O12 (BGO) crystal to evaluate their relative scintillation performance. The glasses were successfully imaged under X-ray excitation, confirming their strong potential as optical probes for medical imaging applications.
The use of rice husk ash (RHA) an agricultural waste not only reduces environmental impact but also contributes to the development of circular economy. The exploration of RHA as a renewable energy resource has enormous potential in promoting sustainable development. The glass composition in this work incorporates silica from RHA derived through sintering processes. A glass system with the composition (60-x)B2O3-xBi2O3-20ZnO-20RHA (x = 25, 35, 45 mol%) was prepared through heavy metal oxide (Bi2O3) substitution using the melt quenching technique. X-ray diffraction (XRD) was used to confirm the amorphous nature of the glasses. The BZRBi25, BZRBi35, and BZRBi45 glass samples exhibit appropriate transmittance in the visible region at a consistent thickness of 1 mm. Fourier transform infrared (FTIR) spectroscopy was used to identify the vibrational modes and their corresponding functional groups. The replacement of B2O3 with Bi2O3 in the prepared glasses resulted in an increase in the density from 4.061 to 4.843 g/cm3. To confirm the accuracy of the values over an energy range of 0.015-15.0 MeV, a comparative analysis was carried out for the gamma ray shielding parameters, namely, the mass attenuation coefficients (mu m), effective atomic number (Zeff), and effective electron density (Neff) estimated by WinXCom software (theoretical), Compton scattering (experimental), and Particle and Heavy Ion Transport Code System (PHITS-simulation). In comparison to standard shielding materials, the examined glasses exhibit reduced half value layer (HVL) values. At an energy of 0.662 MeV, the lead equivalent thickness (Delta eq) of the glass samples increases with increasing concentration of Bi2O3. Additionally, the total mass stopping power (TMSP) and projected range (PR) have been determined for proton particles (H+) and alpha particles (He+2), respectively. A PHITS Monte Carlo simulation was performed at 0.662 MeV to calculate absorbed dose and effective dose rate in a phantom with and without shielding glass. The results indicate that the incorporation of RHA into the eco-friendly radiation shielding glasses has the potential to be an effective replacement for protection against gamma, proton, and alpha radiations.
This study explores the influence of barium oxide (BaO) content on the physical, optical, and gamma-ray shielding properties of borosilicate glass. Glass samples containing 0 to 40 mol% BaO were prepared via the melt-quenching technique. Their physical and optical properties were experimentally characterized using the Archimedes' principle for density measurement and transmittance (%T) evaluation. The radiation shielding parameters were evaluated using a combination of experimental measurements, Monte Carlo simulations (PHITS), and theoretical calculations (WinXCom). The shielding properties of the glasses were examined over a wide energy range of 0.015 MeV-15 MeV theoretically and compared with the simulation results. Experimentally, 133Ba, 137Cs, and 60Co were used as standard sources to generate monoenergetic photons covering an energy range of 0.356 MeV to 1.332 MeV. The findings indicate that increasing BaO concentration enhances the density, attenuation values and EABF, particularly at low to intermediate photon energies. The experimental results revealed that the highest radiation shielding performance was observed at the low energy of 0.356 MeV, where the values of mu, Zeff, Neff, HVL, and Pb-equivalent thickness were found to be 0.35 cm-1, 14.94 e-/atom, 3.26 x 1023 e-/g, 1.92 cm, and 0.35 mm, respectively. BaO 20 glass was fabricated into a large-scale transparent glass sheet to demonstrate its feasibility for use as an observation window from outside radiation-controlled rooms, aiming to enhance environmental safety in future applications.
