Studied Glass System Research Articles

Simulation and calculation of the radiation attenuation parameters of newly developed bismuth boro-tellurite glass system

This paper presents a comprehensive simulation and calculation study of the radiation attenuation parameters for a newly developed bismuth boro tellurite glass system. Through advanced computational modeling and theoretical analysis, linear and mass attenuation coefficients (μ and μ/ρ), and other key radiation attenuation parameters of the studied glass system are thoroughly investigated across a range of photon energies. Utilizing state-of-the-art simulation techniques and theoretical models, the radiation shielding effectiveness of the glass system is evaluated, offering insights into its potential applications in radiation protection and shielding. We found that the ΣR values for fast neutrons are 0.10013, 0.10221, 0.10953, 0.11347 and 0.11383 cm−1 for BTBiBV-1, BTBiBV-2, BTBiBV-3, BTBiBV-4, and BTBiBV-5, respectively. The results of this study contribute to the understanding of the radiation attenuation properties of bismuth boro tellurite glasses and provide valuable information for their utilization in various fields, including medical imaging, nuclear power, and industrial radiography. Additionally, accurate modeling and characterization of attenuation parameters across different photon energies are crucial for designing effective radiation protection strategies and ensuring the safety of personnel and equipment in radiation environments.

Gamma and neutron attenuation of Bi2O3/CaO modified borovanadate glasses for radiation shielding applications

This article investigates the attenuation features of gamma and neutron radiations for Bi2O3/CaO modified borovanadate glasses. We assess the attenuation coefficients, half value layer (HVL), and mean free path (MFP) of a glass system under different radiation sources and energies. By using PHITS simulation platform, this investigation involves examining different configurations of the studied glass system, including variations in composition and thickness, to optimize its effectiveness as a shielding material. The simulation findings offer valuable insights into the radiation shielding properties of the glass system involved. The obtained results reveal that there is a significant impact for adding Bi2O3 to enhance the values of attenuation coefficients and then improve the shielding performance of the glassy system involved. For example, LAC values at 15 keV are 59.15, 151.89, and 230.05 cm−1, for VBC-Bi20, VBC-Bi20, and VBC-Bi20, respectively. Moreover, the MAC values of VBC-Bi20 specimen are higher than those different commercial glasses such as RS 253, RS 253 G18, and RS 323 G19. These insights assist in the design and development of efficient radiation shielding materials for practical applications in industries like nuclear and medical fields.

Influence of ZnCl2 on gamma attenuation and radiation shielding of tellurite glasses containing Bi2O3 and B2O3

This paper investigates the influence of ZnCl2 on the gamma attenuation and radiation shielding properties of tellurite glasses incorporating Bi2O3 and B2O3. Employing Geant4 simulation and XCOM program, the study explores the impact of varying ZnCl2 content on different gamma attenuation parameters such as linear attenuation coefficient (μ), radiation protection efficiency (RPE), effective atomic number (Zeff), and HVL. Moreover, the relation between these factors and the density of the studied glass system is discussed in details. It is found that the incremental addition of Bi2O3 significantly enhanced the photon attenuation properties of the tellurite glasses involved. The maximum Zeff values are observed at the low energy region between 0.015 and 0.1 MeV with the values of 53.016, 60.133, 65.950, 70.370, and 73.791 for the glass samples namely TBBZC1, TBBZC2, TBBZC3, TBBZC4, and TBBZC5, respectively. Furthermore, the HVL values fall between 0.0016 cm and 4.3546 cm indicates that the current glass system can be utilizes for gamma shielding applications. The results provide insights into the potential enhancement of radiation shielding efficiency in tellurite glasses, contributing valuable knowledge for the development of advanced materials in nuclear safety applications.

Radiation shielding features of Na2O–P2O5 glasses doped with MnO experimentally and using FLUKA and Phy-X

This research focused on examining the radiation shielding performance of (50% - x/2)P2O5-(50%-x/2)Na2O-xMnO (where x = 0, 5, 15, 25, and 33 mol%) glass system. The shielding review covered the radiation of photons, electrons, particles of heavy-charged, and neutrons. Hence, multiple parameters such as coefficient of mass attenuation (μm), transmission and buildup factors (HVL, MFP, EBF, and EABF), effective atomic number for samples (Zeff), and removal cross-section for fast neutron (FNRCS) of the selected samples were investigated. The results are determined experimentally and by employing FLUKA Monte Carlo software and Phy-X (ZeXTRA and PSD) theoretical programs. A relative discrepancy (RD) and a root-mean-square error (RMSE) were applied to verify the deviation between FLUKA and Phy-X values. An excellent agreement is noticed between measured, simulated, and calculated results. The research revealed that increasing MnO content improves the gamma, electron and heavy charged particle shielding efficiency of studied glasses. Although the addition of MnO has an insignificant impact on FNRCS (from 0.086 to 0.092 cm−1), obtained results identified the relationship between the packing density and shield ability against neutrons for ternary phosphate glasses. We found that the HVL values dropped from 13.898 cm to 11.568 cm at 15 MeV. A range of 7–12 for gamma, 8–12 for electron, 10–11 for proton, 10–11 for alpha, and 9–11 for carbon ion was the maximum value of Zeff that could be obtained. These glasses' shielding behaviors were contrasted with those of conventional materials. Accordingly, the sample with the highest mole fraction (x = 33 %) has higher shielding efficiency than ordinary concrete, Pyrex, and RS253-G18. Finally, the studied glass system can be a good compromise between highest effectiveness of shielding, lowest fabrication cost and environment-friendly shield.

Glass transition and crystallization kinetics of lithium modified zinc borate semiconducting glasses by non-isothermal method

Glass transition and crystallization kinetics of lithium-modified zinc borate glasses of the system 20ZnO.xLi2O.(80-x) B2O3 (x = 10, 20, 30 and 40) have been studied using the non-isothermal method of differential scanning calorimetry (DSC). The 20ZnO·10Li2O.70 B2O3 glass composition has the highest thermal stability and the glass-forming tendency among all other glasses. The activation energy associated with crystallization ((210–318) kJ/mol)), glass transition ((464–531) kJ/mol)), Avrami exponent (3) and frequency factor (2.49 × 109–2.32 × 1017) were extracted from the fitting of different theoretical models and the values are in close agreement with each other. The value of the Avrami exponent was found ∼3 thereby indicates the occurrence of volume nucleation with two-dimensional growth in the currently studied glass system. The formation of Pure monoclinic LiZnBO3 crystalline phase is observed in 20ZnO·30Li2O·50B2O3 and 20ZnO·40Li2O·40B2O3 glass compositions which is a potential candidate for electric double-layer capacitance fabrication.

Influence of TiO2 concentration on near-infrared emission of germanate glasses doped with Tm3+ and Tm3+/Ho3+ ions

In this work, Tm3+ doped and Tm3+/Ho3+ co-doped germanate glasses with various TiO2 concentrations have been examined using optical spectroscopy. The broad emission bands corresponding to 3F4→3H6 (1.8 μm) and 5I7→5I8 (2 μm) transitions of thulium and holmium ions were registered, respectively. It was observed that the intensity of near-infrared emission bands significantly changes with increasing titanium oxide content in the glass composition. Furthermore, the energy transfer process from Tm3+ to Ho3+ ions in studied glass systems was confirmed and discussed. The dependence of spectroscopic parameters like full width at half maximum (FWHM) and energy transfer efficiency (ηET) on increased TiO2 concentration in glass host was established.

Enhancing the radiation absorption ability of the glass system with the contamination of Heavy Metal Oxide (PbO, CuO, and Bi2O3)‏

Containing the molar percentage recipe of 55B2O3–x PbO–(45-x) CuO [ where, x = 5, 10,15, 20, 25 and 30 mol%] glass systems were particularized in this present study. To detect the radiation shielding features such as linear attenuation coefficients (LAC), mass attenuation coefficients (MAC), half value layer (HVL), mean free path (MFP), effective atomic number (Zeff) of these six glasses by using Phy-X software. The obtained results indicate that the value of the studied glass systems represented the highest value of LAC, MAC, and Zeff whereas the lowest value has found for HVL, and MFP. The value of these parameters represented the utmost shielding ability displayed by the studied glass containing the highest mol percentage of the PbO and CuO. Additionally, it has been seen that the density of the glass systems upsurges due to the greater addition of wt% of the PbO and CuO. The studied glass system S6 (30PbO-15CuO-55B2O3) represented a 5.3 times lower value than sample S1(5PbO-40CuO-55B2O3). That means the highest percentage of PbO and CuO enhances the shielding ability. Noteworthy, it has been found from the studied results that with the increase of incident photon energy the value of HVL has increased. Like at energy 1.33 MeV, the half value layer for studied glass sample S1 (5PbO-40CuO-55B2O3) is approximately 3 cm while S6 is 2 cm. In view of the above facts, it can be easily stated that the studied sample S6 (30PbO-15CuO-55B2O3) has the best shielding ability among the six studied glass samples.

Microstructure, electrical, optical and electrochemical characteristics of silver phosphate glasses cathode for magnesium battery applications

The realization of a practical magnesium battery is combined with the development of a high kinetic cathode and compatible electrolyte to facilitate the redox process. For this reason, silver phosphate glasses in the binary system (Fe2O3–AgPO3) are prepared using the conventional quenching method. The glasses were defined in the form [Fe2O3] x [AgPO3](100−x) and the composition with 0 ⩽ x ⩽ 40 wt. %. The molar volumes and densities were measured. These glass systems were characterized using x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV–Vis–NIR spectrophotometer, electrochemical procedures and impedance spectroscopy. X-ray diffraction revealed that pristine AgPO3 sample was formed in a glassy state, whereas two crystalline phases (AgFeP2O7 and Fe2O3) were formed after the incorporation of Fe2O3 by different concentrations. Bond assignments associated with different functional groups were investigated by an FT-IR spectroscopy. The values of the band gap were decreased with the increase of Fe2O3 content. The effect of grains and grain boundaries in a heterostructure made up of Fe2O3 and AgFeP2O7 crystallites grown in silver phosphate glasses was studied using impedance spectroscopy. The complex impedance, electrical conductivity, and complex electric modulus were measured in terms of frequency and temperature dependency in [Fe2O3] x –[AgPO3](1−x). In the studied glass systems, non-Debye relaxation was observed. Under a variable regime, σ ac conductivity follows a modified Jonscher’s law Arrhenius fitting of multiple relaxation processes in the material yielded activation energy of (0.12 eV–0.271 eV) which support a Maxwell–Wagner relaxation model in the heterostructure glasses at high temperatures and low frequencies. The dc conductivity decreases with iron rate and follows the Arrhenius law with very low activation energy (0.12–0.27 eV. Mg//electrolyte//Glass coin cells are assembled and show an initial discharge capacity of up to ∼564 mAh g−1. These materials are attractive for application in modernistic electrochemical devices because of their great compositional and preparation variety which enables tuning the types and techniques of electrical conduction in the material.

Understanding the physical, optical and gamma ray shielding properties of the PbO-Bi2O3-CdO-B2O3 glass systems

Physical properties, optical properties, and shielding properties were reported herein by varying the amount of bismuth (III) oxide (Bi2O3) and boron oxide (B2O3) on the PbO-Bi2O3-CdO- B2O3 glass systems through Melt quenching technique. After altering the amount of Bi2O3 density studied glass systems have varied from 4.3 g/cm3 - 5.7 g/cm3. With the addition of bismuth oxide, the density, molar volume, and oxygen packing density all rise. As bismuth concentration increases, the indirect band gap reduces, indicating structural changes in the glasses. As bismuth concentration rises, so do the refractive index (n), optical dielectric constant, and reflection loss (RL) characteristics. Ionic nature of current samples is supported by the reduction in electronegativity and rise in polarizability, which reduces the band gap. Linear attenuation coefficients (LAC), mass attenuation coefficients (MAC), half value layers (HVL), and mean free path (MFP) were calculated for photon energy range 0.015–15 MeV via exploiting Phy-X software. Containing supreme amount of Bi2O3 (25% mol) studied glass systems have shown higher values of effective atomic number (Zeff), LAC, MAC along with least values of HVL and MFP considering with other studied glass systems. Results showed that deposition of Bi2O3 on the studied glass systems has boosted their shielding ability.

Evaluation of gamma and neutron shielding capacities of tellurite glass system with Phy-X simulation software

Newly developed glass system H 3 BO 3 –K 2 CO 3 –MgO–TeO 2 –ZnO–AgNO 3 (HKMTZA) was synthesized by high temperature melting method for gamma and neutron shielding. The parameters of gamma and neutron attenuation are computerized utilizing Phy-X/PSD and for photon energies ranging between 15 KeV and 15 MeV. The newly developed tool is used to calculate the shielding parameters such as mass attenuation coefficient ( μ/ρ ), relative parameters effective atomic number ( Z eff ), half-value layer ( HVL ), tenth value layer ( TVL ), mean free path ( MFP ), and fast neutrons ( Σ R ). Meanwhile, Σ R is enabled to assess the capabilities of the neutron shielding. Because of Ag element which has high atom number, HKMTZA6 has highest Z eff and lowest HVL , TVL . The results of this research revealed that Σ R of this HKMTZA glass system increases with the improving of AgNO 3 and the studied glass system possess higher Σ R value, contrasting with T70V27Z3 glass. And it is closed to the leaded brass alloy (LB), and TeO 2 –B 2 O 3 (TB), illustrating that the HKMTZA glass system possesses excellent properties of neutron shielding. • Glass system with gamma and neutron attenuation properties has been fabricated. • A series of relative radiation parameters are derived by Phy-X/PSD. • Value of neutron shielding factor Σ R are carried out in the range of 0.123–0.100 cm −1 . • THZMKA system is a superior shielding material contrast reported glass and concrete.

Evaluation of the radiation shielding characteristics of WO3–MoO3–TeO2/Sb2O3 glasses

ABSTRACT This study reports the WO3–MoO3–TeO2/Sb2O3 glass system by means of its shielding ability against gamma photons, neutrons and charged particles. The studied glass system has two components, namely WO3–MoO3–Sb2O3 (denoted by WMS) and WO3–MoO3–TeO2 (denoted by WMT). The shielding properties of WMS and WMT glass systems were examined by using several theoretical methods and the FLUKA simulation code over energies between 0.1 to 10 MeV for gamma rays shielding application and between 0.01 and 10 meV for neutron shielding ability. The obtained results indicated that both linear attenuation coefficient and mass attenuation coefficient of WMS and WMT glasses are lowest at 6 MeV and they are highest at 0.10 MeV. The minimum half value layers (HVLs) of WMS and WMT glasses are at 0.10 MeV with values of 0.08506, 0.07822, 0.08268, and 0.07257 cm for WMS1, WMS2, WMT1 and WMT2, respectively. Maximum HVLs occured at 6 MeV with values of 3.89233, 3.70118, 3.89804, and 3.63977 cm for WMS1, WMS2, WMT1 and WMT2, respectively. The mean free paths of WMS and WMT glasses modify from 0.12272 to 5.61545 cm for WMS1, from 0.11284 to 4.33968 cm for WMS2, from 0.11928 to 5.62368 cm for WMT1 and from 0.10462 to 5.25107 cm for WMT2. The WMT2 has the largest values of effective electron densities between 0.10 and 0.6 MeV and WMT1 has the largest values between 0.8 and 10 MeV. The largest gamma dose rates are obtained at 10 MeV and the smallest values are obtained at 0.5 MeV. Both cross-sections for fast neutrons and (σ tot) for thermal neutrons change in order of WMS1 < WMS2 < WMT1 < WMT2.

Photon radiation shielding properties of germanate glass systems containing Bi2O3, PbF2, and B2O3

AbstractIn this study, we studied the gamma radiation shielding properties of ternary germanate glass systems containing Bi2O3, PbF2, and B2O3. The glass samples were synthesized by using the traditional melt‐quenching method. X‐ray Diffraction (XRD) measurements were performed to confirm the glassy nature of the synthesized materials. A narrow‐beam transmission geometry equipped with a NaI(Tl) scintillation detector was used to measure experimentally measurable shielding parameters of the samples, like mass attenuation coefficient, linear attenuation coefficient, half‐value layer, and effective atomic number. Measurements were performed at gamma‐ray energies of 662, 1173, and 1332 keV emitted from 137Cs and 60Co radioactive sources. Additionally, all the above parameters were also calculated theoretically in the .015–15 MeV energy region by employing the WinXCOM software to verify the experimental findings. The experimental and theoretical results were found to be in good agreement. The results showed that the 70Ge20Bi10Pb glass system has competitive shielding properties among the studied glass systems and could be a good candidate for radiation shielding applications.

Investigations of the Elastic Moduli of Er2O3 NPs Doped TeO2 – B2O3 – SiO2 Glasses using Theoretical Models

Elastic moduli of {[(TeO2)0.7 (B2O3)0.3]0.8 (SiO2)0.2}1-y (Er2O3 NPs)y glasses with y = 0.01, 0.02, 0.03, 0.04, 0.05 were studied in this work using the theoretical elastic models. The Makishima &amp; Mackenzie, Rocherulle and bond compression models were employed for the study. In the Makishima and Mackenzie model, the packing density was calculated from the bulk glass molar weight and the bulk glass density whereas in Rocherulle model it is determined as the individual oxides. Young, shear and bulk moduli as well as the Poisson ratio were calculated for the glasses in the Makishima and Rocherulle models, while longitudinal, was calculated in addition to young, bulk and shear moduli using the bond compression model. Bond per unit volume number (nb), bulk modulus, bulk modulus ratio (Kbc/Ke), atomic ring size (?) and stretching force constant were also calculated and presented. The values of the Young, bulk and shear moduli obtained from Makishima model increased from 52.854 to 55.335 GPa, 35.754 to 39.862 GPa and 21.080 to 21.809 GPa respectively with Er2O3 NPs composition increase from 1% to 5%.. The Rocherulle model presented increasing values for Young, bulk and shear moduli as 56.910 to 58.432 GPa, 41.452 to 44.450 GPa and 22.385 to 22.809 GPa respectively with Er2O3 NPs composition increase from 1% to 5%. The bond compression model presented much higher values of the elastic moduli compared to the experimentally obtained values and showed an increasing trend as the Er2O3 NPs concentration increases. In the glass network, the atomic ring size value decreased from 0.5698 to 0.5091 nm indicating an increase in the close packing of atoms. Based on the elastic moduli values presented by all the models, Makishima and Mackenzie model presented a more reliable data and hence represents the best model for the studied glass system.

BaAl2Si2O8 polymorphs and a novel reversible transition of BaAlF5 in supercooled oxyfluoride aluminosilicate liquids

Crystallization plays a critical role in realizing the functionalization of glass materials. However, it is imperative to understand the microscopic mechanism of both the formation and the phase transitions of nanocrystals during heat processes. Here, in the as-prepared SiO2-Al2O3-BaF2-Na2O glass, we studied the polymorphic phase transition of BaAl2Si2O8 during heating-cooling circles, and a novel reversible transformation is found by serendipity. Using differential scanning calorimetry (DSC), we observed an endothermic event around 1047 K during heating at 20 K/min to 1173 K, and an exotherm event at 1024 K during the subsequent cooling. Based on the X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM), the reversible process was attributed to the transition between two morphs of BaAlF5 nano-crystal. Na2O introduced in the studied glass system promotes the transformation between hexacelsian (Hexagonal) and celsian (Monoclinic). The results also show the formation of different types of crystals, such as, BaF2, Na5Al3F14 and BaAlF5 etc.

Strengthening Thermal Stability in V2O5-ZnO-BaO-B2O3-M(PO3)n Glass System (M = Al, Mg) for Laser Sealing Applications

Today, the most common way of laser sealing is using a glass frit paste and screen printer. Laser sealing using glass frit paste has some problems, such as pores, nonuniform height, imperfect hermetic sealing, etc. In order to overcome these problems, sealing using fiber types of sealant is attractive for packaging devices. In this work, (70-x)V2O5-5ZnO-22BaO-3B2O3-xM(PO3)n glasses (mol%) incorporated with xM(PO3)n concentration (where M = Mg, Al, n = 2, 3, respectively) were fabricated and their thermal, thermomechanical, and structural properties were investigated. Most importantly, for this type of sealing, the glass should have a thermal stability (ΔT) of ≥80 °C and the coefficient of thermal expansion (CTE) between the glass and panel should be 1.0 ppm/°C. The highest thermal stability ΔT of the order of 93.2 °C and 112.9 °C was obtained for the 15 mol% of Mg(PO3)2 and Al(PO3)3 doped glasses, respectively. This reveals that the bond strength and connectivity is more strongly improved by trivalent Al(PO3)3. The CTE of a (70-x)V2O5-5ZnO-22BaO-3B2O3-xAl(PO3)3 glass system (mol%) (where x = 5–15, mol%) is in the range of 9.5–15.5 (×10−6/K), which is comparable with the CTE (9–10 (×10−6/K)) of commercial DSSC glass panels. Based on the results, the studied glass systems are considered to be suitable for laser sealing using fiber types of sealant.

Effect of Nd3+ ions on radiation attenuation properties of PbF2–TeO2–WO3 glass system for shielding applications

This study aims to investigate the utility of using 15PbF2–(60x)TeO2–25WO3–xNd2O3 (0.1≥x≥1.5) glasses in the nuclear shielding applications for mixed radiation fields at energies ranging from 15keV to 15MeV. The effect of Nd3+ ions on gamma attenuation properties of the present glass system was discussed in detail. The radiation attenuation features were investigated for the present glass system by using Monte Carlo radiation transport simulation via Geant4 toolkit. The simulation results were theoretically approved by using Phy-X approach over the entire considered energy range. The obtained results indicate that the values of Zeff and Neff were both highest in the in the τ/ρ dominated energies due to the atomic number dependence of the cross sections of the τ/ρ absorption processes. Moreover, FNRCS values were 0.1152, 0.1152, 0.1153, and 0.1153cm−1 for PWTN1, PWTN2, PWTN3, and PWTN4 respectively. Finally, an extensive comparative study is also presented between the studied glass system and standard traditional shielding materials. The study suggests PWTN4 is the best photon shield amongst the studied PWTN-glasses.

Gamma-ray shielding studies on borate glasses containing BaO, Bi2O3, and PbO in different concentrations

Mass attenuation coefficients (μm), half value layer (HVL), effective atomic cross sections (σa), effective atomic numbers (Zeff) and effective electron densities (Neff) of borate glasses containing different concentrations of BaO, Bi2O3, and PbO (20–50% by mole) were obtained in the energy range of 10 keV–10 MeV using MCNPX code, XCOM and XMuDat programs, Auto-Zeff software and linear interpolation method. The simulated and calculated results were in good agreement with the experimental data with differences of ≤ ± 11%. It was found that σa and Zeff of glass samples improve by increasing their BaO, PbO and Bi2O3 contents, while increasing these contents to the same fraction has no significant effect on μm values in the energy range of 0.3–6 MeV, where the Compton Effect takes over as dominant process. In addition, the μm and σa values of glasses decreased with photon energy and bismuth oxide borate glass obtained the highest values of μm and σa. Also, HVL values of the studied glasses decreased with the increase in their densities. The 50Bi2O3:50B2O3 glass system had the highest Zeff value of 55.60 at the 30 keV photon energy. Above 0.4 MeV photon energy, Neff values were independent of the metal oxides contents. The Neff values of the studied glass systems varied in the range of 2.77 × 1023 – 9.10 × 1023 electron/g.

Influence of Oxide Glass Modifiers on the Structural and Spectroscopic Properties of Phosphate Glasses for Visible and Near-Infrared Photonic Applications.

The effect of oxide modifiers on multiple properties (structural and spectroscopic) of phosphate glasses with molar composition 60P2O5-(10−x)Ga2O3-30MO-xEu2O3 and 60P2O5-(10−y)Ga2O3-30MO-yEr2O3 (where M = Ca, Sr, Ba; x = 0, 0.5; y = 0, 1) were systematically examined and discussed. The local structure of systems was evidenced by the infrared (IR-ATR) and Raman spectroscopic techniques. The spectroscopic behaviors of the studied glass systems were determined based on analysis of recorded spectra (excitation and emission) as well as luminescence decay curves. Intense red and near-infrared emissions (1.5 μm) were observed for samples doped with Eu3+ and Er3+ ions, respectively. It was found that the value of fluorescence intensity ratio R/O related to 5D0→7F2 (red) and 5D0→7F1 (orange) transition of Eu3+ ions depends on the oxide modifiers MO in the glass host. However, no clear influence of glass modifiers on the luminescence linewidth (FWHM) was observed for phosphate systems doped with Er3+ ions. Moreover, the 5D0 and 4I13/2 luminescence lifetimes of Eu3+ and Er3+ ions increase with the increasing ionic radius of M2+ (M = Ca, Sr, Ba) in the host matrix. The obtained results suggest the applicability of the phosphate glasses with oxide modifiers as potential red and near-infrared photoluminescent materials in photonic devices.

High pressure effect on the short- and intermediate-range structure of depolymerized soda lime silicate glass: Insights from micro-Raman spectroscopy

The network structure pressure dependence of a modified soda lime silicate glass, containing CaF2 and lower SiO2 content, was investigated by micro-Raman spectroscopy. The glass structure was first analyzed under normal pressure conditions in terms of network depolymerization, by comparing with commercial soda lime glass. Using calculation of non-bridging oxygens per tetrahedron (NBO/T), it was found that while commercial soda lime glasses have Q4 and Q3 units, the studied glass system presents a depolymerized structure and it is composed, on average, of Qn with n = 3 and 2. Changes due to high hydrostatic pressure were evaluated by using a diamond anvil cell up to 19 GPa. Raman scattering was used to calculate Si–O–Si angular population according to the network central force, which showed a progressive angle closure with pressure. The Raman spectrum of recovered sample, after compression/decompression cycle, showed negligible changes, suggesting that initial amorphous phase of modified glass is highly stable. The glass showed very high incompressibility, compared to aluminates, silicates, lanthanum borogermanate, or even regular soda lime glasses, suggesting that its bulk modulus is relative high. Polymerized glasses have great space vacancies within the network structure, on the contrary it was observed that the studied glass presents a densely packed structure reflecting on high incompressibility, which decreased the magnitude of permanent densification.

Effect of replacement of Bi2O3 by Li2O on structural, thermal, optical and other physical properties of zinc borate glasses

Zinc bismuth borate glasses modified by lithium oxide with composition (25-x) Bi2O3–60B2O3–15ZnO-xLi2O, where, x = 5, 10, 15, 20 and 25 mol% have been synthesized using standard melt quenching technique. Amorphous nature of the glass samples has been ascertained by appearance of broad hump in X-ray diffraction patterns. FTIR and Raman studies advocated that glass structure is mainly built of [BO4], [BO3] and [ZnO4] structural units, however, Bi2O3 exists primarily as [BiO6] octahedral units. The glass transition temperature (Tg) shows a non-linear variation with increase in Li2O content. Trend in the values of ‘Tg’ is in accordance with change in structure of glass matrix (i.e. fraction of [BO4] units (N4) on addition of Li2O). The values of density (ρ), molar volume (Vm) and crystalline volume (Vc) are found to decrease with increase in Li2O content. The percentage value of transmittance is found to increase with increase in Li2O content. Optical band gap energy ‘Eg’ values has been determined from fitting of experimental data with Tauc’s relation and Hydrogenic excitonic model (HEM) and are found in the range of 2.432–3.211 eV. The HEM model shows good agreement with experimentally observed data, indicates the exciton formation in studied glass system. The values of Urbach energy (ΔΕ) have been estimated by fitting of experimental data with a new empirical relation and its values are found in the range of 0.194 eV–0.294 eV. The values of metallization criterion (M) were found in the range of 0.349–0.401, suggesting that the prepared glasses may be considered as potential candidate for non-linear optical applications.