Influence of Bi2O3/WO3 substitution on the optical,mechanical, chemical durability and gamma ray shielding properties of lithium-borate glasses

Six different lithium bismuth boro-tungstate glasses with chemical composition 20Li₂O-(20-x)Bi₂O₃-xWO₃-60B₂O₃ (x = 0, 1, 2, 3, 4 and 5 mol%) were produced by the quenching method. Then, the glasses were investigated by means of their optical, mechanical, chemical durability and gamma ray shielding properties. Measured values of density and ultrasonic velocities were used to determine the elastic properties of the glasses. The optical band gap determined using the absorbance spectrum fitting (ASF) model was found to decrease under Bi₂O₃/WO₃ substitution. The presence of BO₃, BO₄, BiO₆, and WO₄ structural groups in the glasses was confirmed by Fourier transform infrared spectroscopy (FTIR). The dissolution rate in the glass 20Li₂O–15Bi₂O₃–5WO₃–60B₂O₃ (LBWB5) was found to be 10 times lower than 20Li₂O-20Bi₂O₃– 60B₂O₃. Mass attenuation coefficients (MAC) values of the produced glasses were determined using the MCNPX Monte Carlo code and Phy-X/PSD program. The photon attenuation parameters such as half value layer (HVL), mean free path (MFP), effective atomic number (Z_eff), exposure buildup factor (EBF) and energy absorption buildup factor (EABF) were also studied. The obtained results showed that Bi₂O₃/WO₃ substitution has a direct impact on the photon attenuation abilities of produced glasses. More specifically, HVL values increased from 0.252 × 10^?2 cm for LBWB0 glass to 0.275 × 10^?2 cm for LBWB5 glass. However, different trends were observed for the photon buildup factors for the produced glasses. It can be concluded that the produced glasses have promising structural, optical, and photon attenuation properties to be used for gamma shielding applications.     

Synthesis and properties of tellurite based glasses containing Na2O,BaO, and TiO2: Raman,UV and neutron/charged particle shielding assessments

In this paper, 75TeO₂–5Na₂O–20BaO?xTiO₂ (TNB-Tix with x = 0, 05, 10, and 15) glasses were synthesized by the conventional melt-quench technique using analytic grade tellurium oxide (TeO₂), barium carbonate (BaCO₃), sodium carbonate (Na₂CO₃) and titanium oxide (TiO₂) as starting chemicals. The prepared glasses were studied for their physical features, Raman and UV spectra, and shielding performance against neutrons and charged particles. The optical property was investigated by UV–Vis spectrometry while the structural evolution of the glasses was studied through the Rahman spectra. Charged particles, slow and fast neutrons interaction parameters of the glasses were calculated theoretically and analyzed as well. The prepared glasses were yellowish without any flaws. The mass density of the glasses increased from 5.1 to 5.4 g/cm³ as TiO₂ content declined from 15 to 0 mol%. Also, an improvement in the optical bandgap from 2.89 to 3.2 eV was recorded as BaO content increased concerning TiO₂ while the refractive index declined from 2.43 to 2.35. Generally, the improvement in the TiO₂ content of the glasses produced a rise in the total and scattering cross section of thermal and slow neutrons respectively. In addition, the fast neutron cross section was enhanced from 0.1005 to 0.1015 cm^?1 for TNB-Ti00 – TNB-Ti15 glasses. The charged particle shielding parameters showed a strong dependence on the chemical structure of the glass system. The present glass system displayed good properties that could make them useful in optical and shielding applications.     

Synthesis,FTIR, and mechanical as well as radiation shielding characteristics in Nd2O3-doped bismuth lithium borate glasses

A melt quenching method was applied to fabricate a series of bismuth lithium borate glasses with a chemical composition of 65(B₂O₅) + 20(Bi₂O₃) + (15 ? x)(Li₂O) + x(Nd₂O₃), where x = 0, 1, 2, 3, and 4 mol%. The structural changes in the fabricate glasses were studied via the Fourier transform infrared spectroscopy (FT-IR). The FT-IR spectra of the manufactured glasses indicated the transformation of the structural unit BO₄. The mechanical properties of the produced glasses were evaluated via the ultrasonic measurement (longitudinal and shear velocities) and the Makishima–Mackenzie modulus calculations. Furthermore, the role of Nd₂O₃ in improving mechanical properties was studied theoretically and experimentally and results showed that ultrasonic velocities and elastic moduli decreased with increasing the Nd₂O₃ content. The Young's modulus decreased from 68.47 to 50.61 GPa as the Nd₂O₃ content increased from 0 to 4 mol%, respectively. The gamma ray shielding properties of the studied glass samples were evaluated using the Monte Carlo simulations between 0.223 and 2.506 MeV. The simulated data showed that the fabricated glass without Nd₂O₃ has the highest linear attenuation coefficient, which varied between 0.210 and 0.212 cm^?1 for photons with energies ranging from 0.2234 to 2.506 MeV.     

Newly developed BGO glasses: Synthesis,optical and nuclear radiation shielding properties

In this research paper, we studied the optical and nuclear shielding efficiency of newly developed BGO glasses with the following compositions (in wt%): 32Bi₂O₃–68GeO₂, 42Bi₂O₃–58GeO₂, 47Bi₂O₃–53GeO₂, 52Bi₂O–48GeO₂, 62Bi₂O₃–38GeO₂. BGO glasses were prepared by traditional melt quenching method. To obtain the band gap values of fabricated BGO glasses, optical absorption spectra were used for evaluation of optical properties. The mass attenuation coefficients (μ/ρ) were achieved for prepared glasses at 0.015–15 MeV photon energies employing MCNPX Monte Carlo code and WinXcom program. Moreover, broad-range of nuclear shielding parameters for gamma ray, neutrons and charged particles such as mass attenuation coefficient, half value layer, effective atomic number, buildup factors, mass stopping powers, projected ranges, fast neutron removal cross sections and damage factors were calculated. The refractive index is calculated from E_opt, As Bi₂O₃ concentration is enhanced, E_opt is also increased as well as the optical electronegativity and consequently the refractive index. In addition, the results showed that BIGE5 glass sample with highest Bi₂O₃ contribution has excellent nuclear radiation shielding ability among the other fabricated glass samples.     

Comparative investigation of physical,X-ray and neutron radiation shielding properties for B2O3-MnO2-CdO borate glasses

B₂O₃-MnO₂-CdO ternary oxide glasses with amorphous properties were synthesised using the melt-quenching method. Structural and physical property analyses showed that the amount of non-bridging oxygen and the system stiffness increases, and the oxide network filling is more tightly packed as cadmium oxide (CdO) gradually replaces manganese Oxide (MnO₂) in the glass. The radiation-shielding performance of the B₂O₃-MnO₂-CdO glasses was evaluated using the shielding parameters calculated by the MCNPX simulation and the Phy-X program. Glasses with 40% and 50% CdO loading exhibited an average specific lead equivalent (PbE) of 0.241 and 0.294 mmPb/mm in the medical X-ray diagnostic area at 0.03–0.08 MeV; thus, they could fully meet the specific PbE requirements for application as "protection devices against diagnostic medical X-radiation". Furthermore, their photon attenuation capability is superior to that of various commercial shielding glasses in fast-neutron nuclear applications at 1°–10³ MeV. In addition, compared to the borate glass systems studied in the literature, B₂O₃-MnO₂-CdO glasses have fast neutron removal cross-sections of 0.125 cm⁻¹ at a smaller density of 3.9043–4.8135 g/cm³, making them potentially excellent fast neutron absorbers.     

Ionizing radiation attenuation competences of gallium germanate-tellurite glasses utilizing MCNP5 simulation code and Phy-X/PSD program

Gamma radiation, neutrons, protons, and alphas particles shielding competences for gallium germanate-tellurite (GeO₂.TeO₂.Ga₂O₃) glasses doped with Pr₆O₁₁ were tested. The investigated glasses were named as GTGPr1, GTGPr2, GTGPr3, and GTGPr4. Mass attenuation coefficients (MAC) for the proposed glasses were calculated utilizing Phy-X/PSD program and simulated by MCNP5 simulation codes in the photon energy range of 0.015–15 MeV. With the help of MAC values, the linear attenuation coefficient (LAC), half value layer (HVL), mean free path (MFP), and effective atomic number (Z_eff) were calculated. Moreover, the absorbed dose received from ¹³⁷Cs with activity 10 μCi was calculated in presence of the studied glasses. Buildup factors (BUFs) include exposure buildup factor (EBF), and energy absorption buildup factor (EABF) for all investigated glasses were also calculated. Results reflected that the GTGPr4 glass has the highest MAC, LAC values and lowest HVL among other selected germanate glasses. The values of Z_eff were around 0.04 MeV varied between 43.07 and 48.19, while at 1.5 MeV were between 18.70 and 21.25. The GTGPr1 possesses the highest values of BUFs around the studied range of energy, while GTGPr4 glasses possesses the lowest values. Moreover, the fast neutron removal cross section was (Σ_R = 0.02151 and 0.01942 cm² g⁻¹) for GTGPr1 and GTGPr4, respectively. The investigated glasses can be useful to construct superior radiation shielding materials to use in nuclear medicine applications.     

A closer-look on Copper(II) oxide reinforced Calcium-Borate glasses: Fabrication and multiple experimental assessment on optical,structural, physical,and experimental neutron/gamma shielding properties

This study aimed to fabricate six different Copper(II) oxide reinforced Calcium-Borate glasses with different types of substitutions such as Al₂O₃/V2O₅, BaO₂/V₂O₅, and ZnO/V₂O_5. Accordingly, a depth characterization process has been performed for ACV, BCV and ZCV glasses with a nominal composition of 55B₂O₃–35CaO–9Al₂O₃-0.5CuO-0.5V₂O₅, 55B₂O₃–35CaO-8.5Al₂O₃-0.5CuO–1V₂O₅, 55B₂O₃–35CaO–9BaO₂-0.5CuO-0.5V₂O₅, 55B₂O₃–35CaO-8.5BaO₂-0.5CuO–1V2O5, 55B2O3–35CaO–9ZnO-0.5CuO-0.5V2O5, 55B2O3–35CaO-8.5ZnO-0.5CuO–1V₂O₅. Optical, structural, physical, and experimental neutron/gamma shielding properties of synthesized glasses were determined, respectively. Experiments measuring neutron exposure indicated how well glass samples attenuated fast neutrons. The RADACS software was used to record data from a BF3 gas proportional detector from the Canberra NP-100B series and a 241Am/Be neutron source with a 10 mCi activity. The absorption edge belonging to the samples are found between 420 nm and 480 nm. Our findings showed that the optical band gaps for the samples ranged from 1.179 to 2.022 eV. The wavenumber range of 400–1600 cm^-1 was evaluated for the resulting peaks. The region with the highest band formation was approximately 760–1170 cm^-1. While BCV0.5 and BCV1 glasses with 9% and 8.5% BaO₂ insertion have the largest MAC values ranging between 2.255–0.076 and 2.156–0.076 cm²/g, the lowest MAC values varying between 0.361–0.0761 and 0.366–0.076 cm²/g belong to ACV0.5 and ACV1 glasses with 9% and 8.5% Al₂O₃ addition. Our results showed that the BCV glass family has superior material properties among the fabricated glasses. It can be concluded that BaO₂/V₂O₅ glasses may be used in replacement of Copper(II) oxide glasses to provide monotonic behavior on crucial characteristics while maintaining the greatest density increase for large gamma ray shielding properties.     

The role of cadmium oxides in the enhancement of radiation shielding capacities for alkali borate glasses

The radiation shielding capacity of 80B₂O₃–(20-x) Na₂O–x CdO (where x = 0, 2, 4, 6, 8, 10, 12 and 14 mol%) cadmium-doped sodium borate glasses was evaluated. The linear attenuation coefficient (LAC) of the studied glasses was simulated using the Monte Carlo simulation code (MCNP-5) for gamma photons with energy between 0.01 and 15 MeV. Other pivotal gamma ray shielding parameters such as mass attenuation coefficient (MAC), half value layer (HVL), effective atomic number (Z_eff), and buildup factors (EBF and EABF) for the selected cadmium-doped sodium borate glasses were examined. The achieved data showed that, BNC 8 glass with CdO contents of 14 mol % possesses the highest LAC and varied between 0.0650 and 83.636 cm^-1 and also it has thinner HVL than other BNC glasses and varied between 0.008 and 10.686 cm for gamma ray energy between 0.01 and 15 MeV. Moreover, the removal cross sections of fast neutrons (Σ_R) were also calculated theoretically for the selected cadmium-doped sodium borate glasses. The obtained data shows that the insertion of CdO appears to enhance gamma ray and neutron shielding capacity. BNC8 with CdO content (14 mol%) was found to possess the best shielding parameters among the studied cadmium-doped sodium borate glasses.     

A novel B2O3-Na2O-BaO-HgO glass system: Synthesis,physical, optical and nuclear shielding features

In the current paper, we investigated the impacts of HgO addition on optical, structural and radiation shielding properties of newly developed BNBH glass system, with nominal composition (60-x)B₂O₃+20Na₂O+20BaO + xHgO, where x = 0, 2.5, 5, 7.5, 10, 12.5 and 15. BNBH glasses were produced by traditional melt quenching technique. The structure of the produced glasses was estimated employing XRD and TEM analyses and their amorphous natures were verified. The material densities of the investigated glass samples increased nearly linearly as the HgO concentration increased. The UV–visible absorption spectra of the HgO doped glasses were obtained and it is noticed that the absorption coefficient varies with the increase of HgO concentration. The optical absorption spectra were also utilized to found optical energy band gaps, refraction indices and Urbach's tail energy of the prepared glasses. It was observed that the E_g decrease with the increase of HgO content. Moreover, nuclear radiation shielding parameters of BNBH glasses with HgO additive were obtained for photons, charged particles, and neutrons. It was perceived that the insertion of HgO was improved the protecting competences of the glasses against several nuclear radiation types. The results of this comprehensive study revealed that HgO can be used in the design of new glass systems for shielding studies.     

Impact of TeO2–B2O3 manipulation on physical,structural, optical and radiation shielding properties of Ho/Yb codoped mixed glass former borotellurite glass

In this work, (75-x)B₂O₃-xTeO₂-11Bi₂O₃–10Li₂O-1Ho₂O₃-3Yb₂O₃ (x = 10–60 mol%) mixed glass former (MGF) glasses were prepared by using the melt-quenching method to investigate the effect of mixed glass former between B₂O₃ and TeO₂ on the structural, optical and radiation shielding properties of glass. The amorphous nature of the glass samples was confirmed through XRD measurement. Optical ultraviolet–visible light (UV–Vis) spectroscopy revealed that the direct and indirect optical band gap (E_opt) decreased as TeO₂ content increased except for the anomaly at x = 30 mol% due to the interchanging dominance of bridging oxygen (BO) and non-bridging oxygen (NBO) in the glass network. Both direct and indirect refractive indices, n posted an increment except for x = 30 mol% due to polarizability influence of BO and NBO. Urbach energy, E_u declined thus indicating lesser disorder and less defects on the glass structure. The radiation shielding properties of the glass samples were determined for 15 keV–15 MeV photon energy range by using Phy-X/PSD software. Atomic number-dependent parameters such as mass attenuation coefficient (MAC) and effective atomic number (Z_eff) demonstrated an enhanced performances caused by higher Z of Te over B. Meanwhile, density-dependent parameters such as linear attenuation coefficient (LAC), mean-free path (MFP), half-value layer (HVL) and tenth-value layer (TVL) all exhibited an improvement over TeO₂ concentration due to higher density data obtained.     

Influence of Bi2O3 concentration on barium-telluro-borate glasses: Physical,structural and radiation-shielding properties

In this study, a series of Bi₂O₃ reinforced bariumtelluroborate (TBX) glasses with the nominal composition 20TeO₂ + (50-x)B₂O₃ + 29.5BaO + xBi₂O₃ + 0.5Er₂O₃ (where x=0,5,10,15 and 20 in wt%) were manufactured using traditional melt-quenching method. The structural and compositional studies were performed by using XRD and FTIR spectra. In general, the glass matrix consists of the trigonal-planar and tetrahedral units of borates, tellurate and tellurite groups of tellurites, and the non-bridging oxygen (nBO). In addition to that, BiO₃ and BiO₆ groups are present in top-order glasses. The gamma-ray shielding (γ-RS) ability was evaluated through the vital parameters like the mass-attenuation coefficient (MAC), mean free-path (MFP), half-value layer (HVL), and effective atomic-number (Z_eff). TB20 glass is happened to be the best candidate by giving the highest value for MAC and the lowest MFP and HVL, owing to its large density, 6.922 g/cm³. The fast neutron-removal cross-section (∑R) is assessed to investigate the neutron shielding capacity of TBX glasses. The γ-rays shielding properties of TBX glasses were observed better than some ordinary shields such as barite-concrete and commercial shielding glasses developed by SCHOTT Company.     

Preparation and properties of Ge–Ga–La–S–AgI chalcogenide glass

Chalcogenide glasses of 65GeS₂–(25–x)Ga₂S₃–10AgI–xLa₂S₃ (x=0, 1, 3, and 5 mol%) were fabricated through the traditional melt-quenching method. The effects of addition of La₂S₃ on physical, thermal and optical properties of the glass system were investigated. The results showed that the fabricated glasses possess considerably high glass transition temperature, exhibit improved mechanical property and excellent infrared transmission. A redshift at the visible absorbing cut-off edge is observed with increasing of La₂S₃ content. The direct and indirect optical band gap values are also calculated. Raman spectra analysis indicated that the band at 265 cm⁻¹ decreased in amplitude and a new peak at 230 cm⁻¹ was detected manifesting the formation of La-S bond in the network. In addition, the mid-infrared emission at 3.74 µm of the glasses doped with Tm³⁺ ions was achieved. The results indicated that the glasses are promising materials for mid-infrared applications such as imaging, remote sensing and lasers.     

ZnO– Bi2O3 nanopowders: Fabrication,structural, optical,and radiation shielding properties

The aim of this paper is to the synthesis of ZnO– Bi₂O₃ nanocomposites and characterization their optical, structure, and radiation shielding properties. The microwave –assisted hydrothermal method was adopted for the synthesis of ZnO– Bi₂O₃ nanocomposites coded as 100Z, 25B075Z, and 50B-50Z. The FTIR and UV spectra of the samples were analysed to obtain their optical and chemical structure features. Also, the gamma-ray photon shielding parameters of the nanocomposites were evaluated using the EPICS2017 data library and by Geant4 Monte Carlo simulations for photon energies 1 keV–10 MeV. The FTIR spectrum analysis confirms the chemical bond structure of the samples. On the other hand, the optical bandgap of the nanocomposites decreased from 3.3 to 2.95 eV as the Bi₂O₃ nanoparticles increased in the samples. Obtained values of the mass attenuation coefficients of the samples increased in the order of 100Z, 25B075Z, and 50B-50Z. Value of the effective atomic number varies from 13.91 to 29.55, 20.30–55.97, and 26.70–68.97 for 100Z, 25B-75Z, and 50B-50Z correspondingly. The 100Z, 25B075Z, and 50B-50Z nanocomposites were found to have comparable photon shielding ability with respect to high density common commercial glass shields. The present nanomaterials could be adopted as additives to enhance photon shielding competence of existing composite materials.     

Effect of Bi2O3 on mechanical features and radiation shielding properties of boro-tellurite glass system

This paper focuses on the effect of Bi₂O₃ content (up to 80 mol%) on mechanical features and radiation shielding characteristics of boro-tellurite glasses within TeO₂–B₂O₃–Bi₂O₃ system. The basic mechanical parameters such as oxygen molar volume, packing density, hardness, and elastic moduli were studied based on Makishima–Mackenzie's theory. The shielding studies of the TeO₂–B₂O₃–Bi₂O₃ glasses included gamma, electron and neutron radiations. The newly developed Phy-X/PSD program and Geant4 simulation were used to calculate the shielding parameters such as mass attenuation coefficient (μ/ρ), tenth value layer (TVL), mean free path (MFP), stopping power (ψ_e)), removal cross section (RCS), CSDA range, effective atomic number (Z_eff), and half value layer (HVL). The concentration of Bi₂O₃ content had a significant effect on the gamma shielding competence of the investigated glasses. Form the results of gamma shielding studies, the highest μ/ρ (99.845 cm²/g) occurred at 0.015 MeV for TBB80 and the lowest μ/ρ (0.039 m²/g) occurred at 4 MeV for TBB40. The maximum values of Z_eff for gamma interaction occurred at 0.02 MeV and they were 77.26, 78.81, 79.94, 80.80, and 81.48 for TBB40, TBB50, TBB50, TBB60, TBB70, and TBB80, respectively. The gamma shielding features of the investigated glasses were compared with those of various ordinary concretes, and Pb-free, Pb-based, and commercial glasses. The Bi₂O₃ content had also a considerable influence on the electron shielding competence of the tested glasses. The maximum values of Z_eff for electron interaction occurred at 14 MeV and they were 44.58, 47.72, 50.41, 52.75, and 53.73 for TBB40, TBB50, TBB50, TBB60, TBB70, and TBB80, respectively. The results revealed that the bismuth boro-tellurite glasses could be useful for the shielding against gamma, electron, and neutron radiations, wherein the Bi₂O₃ content can be balanced according to the type and energy of radiation.     

Radiation attenuation and optical features of lithium borate glasses containing barium: B2O3.Li2O.BaO

The influence of BaO on the optical characteristics and nuclear radiation shielding properties for 60B₂O₃-(40-x)Li₂O-xBaO: x = 0, 5, 10, 15, and 20 mol% glasses was investigated. Various optical parameters such as optical transmission and reflection loss (T^Optical, R^Loss), molar refraction and molar polarizability (R^Molar, α^Molar), optical and static dielectric coefficients and metallization criterion (ε^Optical, ε^Static, M^Criterion), and metallization property according to refractive index and optical energy gap (M(n^Linear), M(E^Optical)), were determined. The results confirmed that R^Molar changes directly with α^Molar, while T^Optical changes inversely with R^Loss. The mass attenuation coefficient (μ/ρ) was investigated using WinXCOM software and the results showed that all the S1–S5 glasses have good attenuation ability at 284 keV due to their high mass attenuation coefficients (μ/ρ). The highest and lowest values of μ/ρ occurred at 284 keV and 1.33 MeV respectively and varied between 0.1055 and 0.1361 cm²/g and 0.0526–0.0534 cm²/g. The linear attenuation coefficient (μ) increased with the gradual addition of BaO from glass S1→S5. The results showed that the effective atomic number (Z_eff) for S1 is almost constant, while S5 possessed the highest Z_eff values. The half value layer (HVL) was estimated and the effect of BaO on this parameter was analyzed. At 284 keV, the HVL values were 2.8192, 2.3847, 2.1597, 1.9687 and 1.8936 cm for S1–S5 glasses respectively. The S5 sample possessed the least HVL, and accordingly, had better attenuation capabilities than the S1–S4 samples. Therefore, lithium borate glasses with high concentration of BaO can be applied in several optical and medical applications.     

Physical,optical and gamma radiation shielding competence of newly boro-tellurite based glasses: TeO2–B2O3–ZnO–Li2O3–Bi2O3

Herein, a traditional melt quenching method was utilized to synthesize glasses with a nominal chemical composition (80-x)TeO₂-xB₂O₃–5ZnO–5Li₂O₃–10Bi₂O₃: 30≤ x ≤ 80 mol%). The produced sample was coded as TBBZL30 to TBBZL80. X-ray diffraction (XRD) has been employed to test the amorphous nature of the synthesized samples. In the range of 200–500 nm wavelength, UV–Vis spectra for the glasses have been performed. Optical energy gaps ($E_{gap}$) have been determined based on the absorption measurements. With the help of ($E_{gap}$), refractive index (n), molar polarizability (α^M), metallization criterion (M^Cri.), molar refractivity (R^M), static dielectric constant (ε^Sta.), optical dielectric constant (ε^Opt.), reflection loss (R^L) and optical transmission (T^Opt.) have been calculated. For the fabricated boro-tellurite glasses, Phy-X/PSD was used to report some shielding factors for several energies between 15 keV and 15 MeV. The maximum attenuation for all samples took place at 15 keV and the mass attenuation coefficient varied between 52.309 and 57.084 cm²/g. The linear attenuation coefficient (LAC) results demonstrated that TBBZL80 has the highest attenuation than the rest of samples which is due to high content of TeO₂ (containing 80 mol% of TeO₂) whereas TBBZL30 has the lowest attenuation. The LAC for the fabricated samples varied between 230.160 and 351.064 cm-¹ at 15 keV. The minimum effective atomic number (EAN) occurred between 0.8 and 4 MeV and varied between 15.16 and 17.35 for TBBZL30 and 25.10–28.33 for TBBZL80. The addition of TeO₂ was found to enhance the EAN and improved shielding properties for the tested TBBZL glass systems.     

Assessment of interatomic parameters for the reproduction of borosilicate glass structures via DFT-GIPAW calculations

Borates and borosilicates are potential candidates for the design and development of glass formulations with important industrial and technological applications. A major challenge that retards the pace of development of borate/borosilicate based glasses using predictive modeling is the lack of reliable computational models to predict the structure-property relationships in these glasses over a wide compositional space. A major hindrance in this pursuit has been the complexity of boron-oxygen bonding due to which it has been difficult to develop adequate B–O interatomic potentials. In this article, we have evaluated the performance of three B–O interatomic potential models recently developed by Bauchy et al [J. Non-Cryst. Solids, 2018, 498, 294–304], Du et al [J. Am. Ceram. Soc. https://doi.org/10.1111/jace.16082 ] and Edèn et al [Phys. Chem. Chem. Phys., 2018, 20, 8192–8209] aiming to reproduce the short-to-medium range structures of sodium borosilicate glasses in the system 25 Na₂O x B₂O₃ (75 − x) SiO₂ (x = 0-75 mol%). To evaluate the different force fields, we have computed at the density functional theory level the NMR parameters of ¹¹B, ²³Na, and ²⁹Si of the models generated with the three potentials and the simulated MAS NMR spectra compared with the experimental counterparts. It was observed that the rigid ionic models proposed by Bauchy and Du can both reliably reproduce the partitioning between BO₃ and BO₄ species of the investigated glasses, along with the local environment around sodium in the glass structure. However, they do not accurately reproduce the second coordination sphere of silicon ions and the Si–O–T (T = Si, B) and B-O-T distribution angles in the investigated compositional space which strongly affect the NMR parameters and final spectral shape. On the other hand, the core-shell parameterization model proposed by Edén underestimates the fraction of BO₄ species of the glass with composition 25Na₂O 18.4B₂O₃ 56.6SiO₂ but can accurately reproduce the shape of the ¹¹B and ²⁹Si MAS-NMR spectra of the glasses investigations due to the narrower B–O–T and Si-O-T bond angle distributions. Finally, the effect of the number of boron atoms (also distinguishing the BO₃ and BO₄ units) in the second coordination sphere of the network former cations on the NMR parameters have been evaluated.     

Coloration and Nonlinear Optical Properties of ZnTe Quantum Dots in ZnO–TeO2–P2O5 Glasses

ZnO–TeO₂–P₂O₅ glasses were prepared by melt‐quenching method. The color of the glass samples changed from colorless to pale red and dark red with increasing TeO₂ content. Coloration mechanism and nonlinear optical properties of ZnO–TeO₂–P₂O₅ glasses have been investigated. Raman spectra and transmission electron microscope measurements indicated the precipitation of ZnTe quantum dots in the glasses and ZnTe quantum dots are the origin of coloration. Z‐scan technique was used to examine the nonlinear optical properties of the glasses. The glass sample with 30 mol% TeO₂ exhibits large third‐order nonlinear optical susceptibility of 10^?11 esu.     

Gamma radiation attenuation characteristics for lithium-zinc-tellurite glasses using Geant4 code and PDS computer software

Six glass samples with the composition of TeO₂-Li₂O-ZnO were analyzed for their radiation shielding properties. The radiation shielding factors for the lithium-zinc-tellurite glasses were reported using the Geant4 code and Phy-X/PSD program. The transmission factor (TF) was determined for different thicknesses and the results revealed that the TF decreases with increasing the thickness of the glass. For TeLiZ1, increasing the thickness of the sample from 0.4 cm to 1.6 cm led to decrease the transmission of the photon from 0.84 to 0.48 at 0.5 MeV and from 0.94 to 0.76 at 4 MeV. The radiation protection efficiency (RPE) results showed that a thicker glass sample absorbs a higher number of photons, implying that lower radiation pass among the glass, increasing RPE. Also, the glass coded as TeLiZ6 has higher RPE than that of TeLiZ1 glass which suggests that at higher content of TeO₂ (85 mol%), the more efficient the glass is at shielding the incoming photons. The linear attenuation coefficient (LAC) obtained by both methods (Geant4 and Phy-X/PSD showed a good agreement for all the glasses and at all investigated energies. The LAC indicates a strong energy dependence, especially at low energies. The LAC also increases as more TeO₂ is added to the glasses. TeLiZ6 (85TeO₂-15Li₂O, ρ = 5.164 g/cm₃) has the highest RPE and lowest TF, while TeLiZ1 (60TeO₂-15Li₂O-25ZnO, ρ = 4.976 g/cm³) has the lowest RPE and highest TF. The tenth value layer (TVL) was also determined and it was observed that TVL increases with increasing energy, reaching a maximum value at 10 MeV and varying between 12.919 and 13.808 cm. By contrast, the minimum TVL is reported at 15 keV and varies between 0.0106 and 0.0112 cm. The addition of TeO₂ decreases the TVL, with TeLiZ6 having the least TVL.     

Synthesis,physical, optical,mechanical, and radiation attenuation properties of TiO2–Na2O–Bi2O3–B2O3 glasses

A series of bismo-borate (50-x)B₂O₃-xTiO₂-15Na₂O–30Bi₂O₃ glass samples (where x = 0, 2.5, 5, 7.5, and 10 wt%) doped with TiO₂ were fabricated via the melt-quenching technique. The gamma and neutron shielding, physical, optical, and mechanical properties of the prepared samples were investigated. The experimental results were measured using an HPGe detector. ¹⁵²Eu, ¹³³Ba, ¹³⁷Cs, and ⁶⁰Co radioactive sources were used with energies in the range of 81–1408 keV. The experimental results were compared with both the FLUKA code and the XCOM database. The addition of TiO₂ increased the density of the glass samples and decreased their molar volume. The mass attenuation coefficient (MAC) decreased as photon energy decreased, while it increased as TiO₂ concentration increased. The half value layer (HVL) and mean free path (MFP) of the glass samples increased when the photon energy increased and decreased as the TiO2 concentration increased. The absorbance of the present samples is enhanced by using TiO₂, meaning they can be used to protect humans from UV light. Both direct and indirect band gaps decreased as TiO₂ content increased from 0 to 10 wt %. Moreover, the electronic transition between localized states is valid in the present samples. The radiation shielding, optical, physical, and mechanical properties of the fabricated glass samples demonstrate their utility for diagnostic gamma shielding.