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Trivalent erbium ions doped (48 – x) AlPO4 + 15K2O + 12MgF + 20Na2O + 5NaF + xEr2O3 glass samples have been prepared utilizing the melt-quench process and studied to understand the efficacy of Er3+ ions content on physical, structural and luminescence attributes of host glass. The functional groups of the glass structure such as metaphosphate, orthophosphate and pyrophosphate have been elucidated through Fourier Transform Infrared (FTIR) spectroscopic investigation. The least-square approach was used to calculate the Judd–Ofelt parameter from the oscillator strength of the Er3+ ion transitions. The luminescence emission data captured in the visible and near-infrared (NIR) province using 380 and 980 nm excitation wavelengths. The up-conversion (recorded at the excitation at 980 nm) of 0.5 Er glass exhibited emission at 664, 550 and 488 nm wavelengths. The decay plots of the studied glass specimens were measured at 980 nm excitation. The McCumber (MC) theory has been implemented to calculate the gain coefficient of the 0.5 Er glass and flat gain curve was drawn for S-band, C-band and L-band. The attributes for optical amplification were ascertained, including the quality factor (0.85), branching ratio (1), stimulated emission cross-section (1.3 × 10–20 cm2), gain bandwidth (1.26 × 10–25 cm3) and optical gain (0.394 × 10–23 cm2 s) for 0.5 Er glass. The yellowish green light emission ability of the 0.5 Er glass after 980 nm excitation evident through CIE co-ordinates position (x 0.36, y 0.58) at 1931 CIE chromaticity diagram. The spectroscopic and luminescence results endorse that the alumino–phosphate glass specimens loaded with 0.5 mol% of Er2O3 are beneficial for NIR and green light emission applications. [ABSTRACT FROM AUTHOR]

This paper reports on the structural, optical and luminescence studies of Dy3+–Eu3+ co-doped glass ceramics that are obtained via thermal treatment method. The initial confirmation on glass ceramics with the formation of NaBSiO4 crystalline phase was made through XRD study. The FTIR study showed the vibrations of network formers (B2O3, SiO2) and other functional groups. The quantity of non-bridging oxygens (NBOs) are increased in the glass ceramics with increase in annealing temperature. The absorption spectra (UV–visible-NIR) showed the possible transitions of Dy3+ and Eu3+ ions in the glass ceramics. A red-shift in the absorption band-edge and reduction in the optical band gap values were obtained for glass ceramics owing to their heating temperatures. Photoluminescence studies showed the excitations of Dy3+ and Eu3+ ions under 575 nm and 613 nm emission wavelengths. The obtained NaBSiO4 crystalline phase in the glass ceramics has enhanced the luminescence intensity, and lifetimes of Dy3+ and Eu3+ ions compared to unheated precursor glass when excited under 350 nm and 393 nm. Color chromaticity diagram and correlated color temperature (CCT) values showed a shift in the color of light from warm white of precursor glass to neutral white of glass ceramics. The overall results justify the possibility of considering the Dy3+-Eu3+ co-doped glass ceramics as efficient materials for solid-state lighting applications like W-LEDs. [ABSTRACT FROM AUTHOR]

The lanthanum sodium borate glass of composition xSm2O3-yAgCl-(80-x-y)B2O3–15 Na2O-5La2O3 (where x = 0.5 and y = 0.1 mol %) was prepared and heat treated at a constant temperature of 450° C with different annealing schedules of 10, 20 and 30 h durations to enable the formation and growth of the Ag nanoparticles. Transmission electron microscope measurements revealed the existence of Ag nanoparticles in the examined glass specimen. The strong red emission was observed for 4G5/2 → 6H7/2 inherent transition of samarium ions in the titled glass samples. The robust emission and excitation intensities of Sm3+ ions are at 10 h annealing durations, and then decrease with increasing annealing durations due to the quenching effect. The transition and radiative properties of various excited levels of Sm3+ in the titled glass series were estimated, including the branching ratios, stimulated emission cross-section, radiative lifetime, and radiative transition probabilities. The improved luminescence results and better JO features for the 4G5/2 → 6H7/2 emission transition suggest the glass specimens routed with Ag nanoparticles are beneficial for optoelectronic and photonic applications. [ABSTRACT FROM AUTHOR]

In this paper, series of perovskites ceramics (CaTiO3, BaTiO3–SrTiO3) added with 1.0 wt.% of tin oxide SnO2 were fabricated through the solid-state reaction process. The different specimens' structural and functional groups examinations were investigated by using X-ray and Fourier transform infrared spectrophotometer (FTIR) techniques. The surface morphology and elemental composition were examined by scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX). The XRD peaks of CaTiO3 and BaTiO3–SrTiO3 were indexed to the orthorhombic and cubic perovskites, respectively. The inclusion of tin oxide into the prepared ceramics caused shifting in the position of the peaks towards higher angles resulting in deformation in the crystal structure of the ceramics. FTIR results confirmed the formation of the desired compositions. The average grain size increased upon the addition of ton oxide into CaTiO3 and BaTiO3–SrTiO3 ceramics. In addition, the radiation shielding performances were examined. The results showed that the addition of SnO2 to the CaTiO3 and BaTiO3–SrTiO3 ceramics enhances the shielding properties of these ceramics. The linear attenuation coefficient (LAC) at a gamma photon energy of 0.015 MeV enhanced from 72.186 to 73.115 cm−1 when the SnO2 increase from 0 to 1 wt.% for samples CTO and CTO@SnO2, respectively. In this regard, the LAC coefficient of BTO–STO is 168.813 cm−1, and it is enhanced by adding 1 wt.% of SnO2 to be 171.004 cm−1 for sample BTO–STO@SnO2. The results also illustrate a decrease in the ceramics half-value layer and the gamma-ray transmission factor with the addition of the SnO2 in the ceramic matrix. The results obtained validate the possibility of applying the manufactured ceramics for radiation protection purposes. [ABSTRACT FROM AUTHOR]

The present work explores the glass system of (50 + x)PbO–5BaO–5WO3–10Na2O–(30−x)B2O3 (x: 0, 5, 10, 15, and 20 mol%) for radiation shielding applications. For this purpose, five distinct glass systems (PbBaW50–PbBaW70) have been fabricated via conventional melting technique. The fabricated glass series was then investigated in terms of physical, mechanical, and photon shielding properties. According to the physical determinations, the glass density increases from 5.22881 to 6.50914 g.cm−3 as the PbO ascends from 50 to 70 mol%. On the other hand, the change of the PbO concentration in the respective samples affects the mechanical properties (Makishima and Mackenzie model) due to the change in composition and density of the samples. That is, the values of Young's, Bulk, Shear, and Longitudinal moduli are nearly the same with the slight decreasing trend for all the moduli, respectively, as the PbO increases. Further, the Poisson's ratio decreases from 0.179 to 0.171 while the value of fractural bond connectivity ranges from 3.516 to 3.624, and the hardness increases from 2.195 to 2.252 GPa with the increase in PbO concentration. For radiation shielding features, the Phy-X/PSD computations revealed that linear attenuation coefficient (LAC)@0.3029 MeV were equal to 1.627, 1.770, 1.921, 2.062, and 2.223 cm−1 for PbBaW50 to PbBaW70 samples, respectively. By considering LAC determinations, other significant parameters such as mass attenuation coefficient, half-value layer, tenth-value layer, mean free path, and effective atomic number were evaluated. As a result of these findings, one can report that the increasing doping rate of PbO leads to achieving more-performanced radiation shielding materials. [ABSTRACT FROM AUTHOR]

In the the present work, we discussed in detail the X-ray shielding behavior of the glasses in the composition of TeO2-Li2O-GeO2-ZnO-Bi2O3 for the energy range of 30.82–303 keV. Some essential radiation shielding parameters have effectively been evaluated via EPICS2017 library. EPICS2017 showed a relative change between 0.67%—8.23% from the Phy-X software mass attenuation coefficient (MAC) calculations. According to the findings, one can report that the linear attenuation coefficient (LAC) was enhanced for all photon energies owing to the insertion of 15 mol% Bi2O3. From these results, the authors evaluated the thickness variations by finding the half-value layer (HVL), and it was seen that BiTe1 was equal to 0.323 cm while BiTe2 to BiTe4 were equal to 0.221, 0.172, and 0.144 cm in the respective order, at 0.1606 MeV. Similarly, the tenth-value layer (TVL), mean free path (MFP), and effective atomic number (Zeff) were improved by far the best via sample-BiTe4 (highest Bi2O3 concentration). [ABSTRACT FROM AUTHOR]