Glass Structure Research Articles

2.7μm luminescence and structural properties of Er3+-doped fluorotellurate glass

In this paper, the thermal properties and internal structures of fluorotellurate glasses with different concentrations of TeO2 were studied. Glass samples with a concentration of 30mol% TeO2 were doped with different concentrations of Er3+ (1,2, 3,3.5,4,4.5,5mol%) and their luminescence characteristics were analyzed. The fluorotellurate glass possess high infrared transmittance (93 %), thermal stability (ΔT>110 °C), and low phonon energy (821 cm−1). Er3+ doped fluorotellurate glass exhibits high fluorescence lifetime of 4I11/2 level (1.59 ms), large emission cross-section (5.98 × 10−21cm2), and achieves a quantum efficiency of up to 30 %. These experimental findings suggest promising prospects for the utilization of Er3+ doped fluorotellurate glass in 2.7 μm laser applications.

Synthesis, and impact of GaN deposition on the physical, optical, and structural properties of Nd3+-doped Na2O borate glasses prepared with soda lime (SLS) glass as a silica source

A novel Nd2O3-doped recycled SLS glasses sputtered with GaN were synthesized using the common melt-quenching method. The synthesized glassy samples were investigated by characterizing them structurally, physically, and optically. XRF revealed a SiO2 content of 70.81 wt% from the SLS sample. XRD discovered the amorphous nature of the studied glasses. FTIR confirmed the structural alterations and presence of functional groups. With the inclusion of Nd2O3, the Vm, and ρ increased due to the greater Mwt of Nd2O3 and the wider ionic radius of Nd3+ creating more NBO thereby expanding the glass structure. Using the Tauc model, the Egopt was derived. The direct band gap decreased from 3.51 to 3.38 eV with increasing Nd2O3, however the indirect band gap shows an energy increase, from 2.01 to 2.25 eV. The refractive index decreased with increasing Nd2O3 while the Urbach energy increased with Nd2O3. The influence of the GaN target deposited on the glass surface using RF sputtering is noticed clearly in the sample's surface morphology (AFM) which increases the root-mean-square (RMS) roughness value from 571 to 872 nm which is confirmed in the FESEM results.

The impact of gamma-ray doses on structural, optical, and mechanical features of tellurite glass modified with different oxides for use in radiation shielding field

This work investigates the effect of gamma-ray doses on the glass structure and optical properties of BaO–TeO2 modified with different oxides, such as Bi2O3, TiO2, MnO2, and MoO3, for possible use in the radiation shielding field. Five glass samples were fabricated and given codes: BaTe, BaTeBi, BaTeTi, BaTeMn, and BaTeMo. The structural and optical properties were investigated pre- and post-irradiation by a 100 kGy gamma-ray dose. The intensity of Raman spectra for the BaTe sample was impacted by the gamma-ray dose, which diminished with exposure to gamma rays while adding different modifiers enhanced the glass stability against gamma-ray dose. In contrast, the gamma-ray dose raised the band gap (Eg) for all glasses except the BaTe and BaTeBi samples. The mechanical properties of glasses showed variation with the addition of various oxides, indicating a different role for each one. Here, the BaTeMo and BaTeTi showed the highest mechanical properties. The linear attenuation coefficient (LAC) at 0.184 MeV for BaTe, BaTeBi, BaTeTi, BaTeMn, and BaTeMo was 1.967, 3.393, 1.831, 1.851, and 2.044 cm−1, respectively. The BaTeBi sample recorded the highest shielding performance compared to other glasses. It can be concluded that the BaTeBi sample is a suitable material for the shielding field due to its superiority in radiation shielding properties and no variation with exposure to gamma rays based on optical properties and Raman spectroscopy.

Development of blue-light absorbing silicate glasses through codoping with TiO2, CeO2, Fe2O3, and Bi2O3

The high energy of blue light (approximately 460 nm) emitted from display components may lead to ocular pathologies. Therefore, the development of glass compositions resistant to blue light is crucial. In this study, TiO2, CeO2, Fe2O3, and Bi2O3 were doped into a Na2O–CaO–Al2O3–SiO2 glass composition. The required properties of the glasses are to reduce the transmittance at 460 nm (T460) to less than 50 %, while maintaining high transmittance at longer wavelengths (T550 > 70 %, and T700 > 80 %). The glasses were prepared using the conventional melt-quench method. The cast glasses were analyzed using a UV–visible spectrophotometer to obtain the transmittance spectra ranging from 200 to 800 nm. The reflectance (R) of glass powder compacts was measured using a spectrophotometer equipped with a reflectance integrating sphere. This data was then used to derive the Kubelka-Munk function, F(R), which can display absorption peaks. After deconvolution, the contributions of each doping ion were obtained. Based on the experimental results, the dopant-free glass is colorless, with a cutoff wavelength (λc) of 213 nm and T460/T550/T700 of 90/91/92 %. All four types of dopants increase λc and decrease the transmittance. The combination of Ti–Ce–Fe–Bi dopants is relatively more likely to meet the transmittance requirement. The contributions of Ti4+, Ce4+, Ce3+, Fe3+, and Bi3+ ions to the UV-blue absorption as well as their potential redox tendencies are discussed. Raman analysis reveal that the dopants mainly act as network modifier in the glass structure, increasing the number of non-bridging oxygen. This effect also contributes to the red shift at the absorption edge.

Influence of temperature and flow rate on alteration layer structure and leaching properties of simulated sulfur-containing borosilicate HLW glass under multi-field coupling effects

During long-term deep geological disposal process, high-level liquid waste (HLW) glass may be exposed to “Thermodynamics-Hydrodynamics-Mechanics-Chemistry” (THMC)multi-field coupling effects. The leaching properties of sulfur-containing borosilicate HLW glass at different temperatures (40–150 °C) and different flow rates (0.01–0.10 mL/min) under THMC coupling effects were studied in this work. The alteration layer structure of waste glass surface was also characterized. The results show that honeycomb-shaped phyllosilicate alteration layer forms after leaching in simulated groundwater and white block-shaped BaSO4 crystals appear on the glass surface at 90 °C after 28 d. The amount of BaSO4 crystals increases obviously at 150 °C. The leaching rates of B, Si, Cs and U elements increase with increasing temperature and flow rate. Particularly, the leaching rates of B, Si, Cs, and U under THMC coupling effects (90 °C, 0.01 mL/min, 10 MPa, pH=8.05) after 28 d in the simulated groundwater are 1.10 × 10–1, 1.73 × 10–1, 2.91 × 10–1, 3.79 × 10–1 g·m-2·d-1, respectively.

Tailoring structural, thermal, and optical properties of Tm3+-doped borotellurite glasses through Bi2O3 incorporation for optical fiber construction

This research investigates the influence of bismuth oxide (Bi2O3) on the structural, thermal, and optical properties of thulium (Tm3+) ion-doped borotellurite glasses, aiming to optimize materials for optical fiber construction. Melt-quench method was employed for glass preparation. XRD spectra indicated that all the synthesized glass samples exhibit an amorphous structure. By methodically increasing the Bi2O3 content to 0.1 molar fraction, significant improvements were observed in the glass matrix. These improvements include increased optical band gaps and decreased Urbach energy, indicative of reduced structural disorder and enhanced homogeneity. which are crucial for minimizing optical losses in fiber optics. Infrared (IR) spectroscopy analysis revealed that this optimal Bi2O3 content leads to denser, more ordered glass structures with an increase in bridging oxygens and a reduction in non-bridging oxygens, contributing directly to the observed improvements in optical properties. Additionally, thermal analysis highlighted a notable enhancement in the thermal stability of the glasses, highlighting their suitability for enduring variable temperature conditions and ensuring durability in optical fiber infrastructure. The findings support for the potential of these doped borotellurite glasses in advancing the development of robust, high-performance optical fibers capable of withstanding environmental challenges.

Evaluating the physico-chemical properties of water-based and 2% lidocaine hydrochloride-based aluminum-free glass polyalkenoate cements for distal radius fixation.

Lidocaine hydrochloride is used as an anesthetic for clinical applications. This study considers the effects of the substitution of 2% lidocaine hydrochloride for deionized (DI) water on the rheological, mechanical, ion release, pH and injectable properties of two formulations of aluminum-free glass polyalkenoate cements (GPCs) using two distinct poly(acrylic) acids (PAA), E9 and E11, which have different molecular weights (Mw). The substitution of 2% lidocaine hydrochloride demonstrated increased injectability, but did not affect mechanical properties. The mechanical properties increased with time, as expected, and, in general, E9-based GPCs displayed significantly higher strengths over E11-based GPCs. With respect to ion release, which includes calcium (Ca), strontium (Sr), zinc (Zn) and silicon (Si); all ions displayed a steady and consistent increased release over time. Ca and Sr showed similar ion release patterns, whereby the GPC made with E11 PAA and lidocaine hydrochloride released significantly more ions than all other compositions likely due to similar chemical kinetics. However, Zn is also divalent in nature, but displayed only one significant difference across the GPC series at all time points, which was attributed to its higher electronegativity allowing for increased participation in the setting reaction. Finally, an analysis of the pH confirmed an increase in pH with time, suggesting that H+ ions were attacking the glass structure to allow for ion release. After 1 and 7 days, water-based GPCs environments achieved a higher pH than lidocaine hydrochloride-based GPCs, indicating that the lidocaine hydrochloride may be releasing additional protons upon bond formation with PAA.

First-ever fusion of high entropy alloy (HEA) with glass: Enhancing of critical properties of zinc-tellurite glass through TiZrNbHfTaOx incorporation

Many oxide additives have historically been used to enhance the radiation shielding properties of glasses, yet the potential of high-entropy oxides (HEOs), which have gained popularity in material science for their unique properties, has not been explored in this context. This study is the first to investigate the radiation shielding capabilities of Zinc-Tellurite glass infused with High Entropy Oxide (HEO), specifically utilizing the novel attributes of a synthesized TiZrNbHfTa. In this study, the nuclear shielding properties of newly fabricated Zinc-Tellurite glasses doped with TiZrNbHfTaOx with a composition (25ZnO·75TeO2)100-x. (TiZrNbHfTaOx)x (x = 0, 1, 2, 3, 4 mol%) were studied. Through the synthesis of a TiZrNbHfTa HEA and its integration into glass structure, we have developed a series of novel materials with enhanced protective properties against both gamma-ray and neutron radiation. Experimental results demonstrate that the HEO-infused glass, particularly the HEC1-4 composition, significantly surpasses traditional shielding materials in neutron attenuation, evidenced by its superior effective neutron removal cross-section. Additionally, the HEC1-4 glass demonstrates improved gamma-ray shielding capabilities, with increased mass attenuation coefficients and decreased half-value layers, indicating a higher capacity for photon interaction and absorption. It can be concluded that the incorporation of High Entropy Alloys into glass matrices not only opens a new frontier in radiation shielding materials but also provides a versatile and effective solution with considerable potential for enhancing safety measures in radiation-prone environments.

Mechanical and structural properties of monatomic zirconium metallic glass under pressure variations and annealing processes: A molecular dynamics study

The aim of this study is to investigate how different pressure levels and annealing times affect the local atomic structure and mechanical properties of pure zirconium metallic glasses. Using molecular dynamics simulations with the embedded atom method, we explored how these changes influence the material's inherent characteristics. Analysis of the radial distribution function, coordination number, and Voronoi tessellation revealed a spectrum of structural arrangements in metallic glass formed across a pressure range of 0–70 GPa. Additionally, the glass transition temperature increased with increasing pressure, accompanied by reduced free volume. The annealing process, ranging from 0 to 5 ns on metallic glass synthesized under 0 GPa pressure, showed the coordination number's significance in achieving a glassy state. Regarding mechanical behavior, both elastic constants and moduli showed a progressive increase with rising pressure, while Young's modulus and hardness displayed enhanced values with longer annealing times.

Glass Beams Used in Steel-glass Roofs for the Adaptive Reuse of Historic Buildings

This article concerns the use of structural glass in the adaptive reuse of historic facilities using glass beams as structural elements in steel-glass roofs. More and more often, glass is increasingly being used as a structural material. This fact provides new design possibilities in the adaptation of historic buildings due to the neutral perception of glass and, at the same time, offers the possibility of distinguishing modern structural elements in the historic fabric. The use of structural glass is, however, associated with limited spans of structural elements. For larger spans, solutions of mixed materials are proposed, which are exemplified by steel-glass roofings. Based on selected examples, steel-glass systems with the use of glass beams are characterised. The strength of glass as a structural material is discussed. The main approaches in the design of glass beams with the lateral-torsional buckling phenomenon are indicated.

Exploring the thermoluminescence characteristics of smartphone screen safety glasses for retrospective dosimetry applications

In clinical settings, standard dosimeters might miss radiation mishaps. Retrospective dosimeters could help to track personnel (such as patients and other staff who don't wear dosimeters) exceeding safe limits and assess long-term exposure trends. This study has investigated key thermoluminescence (TL) dosimetric characteristics, including the glow curve structure, dose-response, energy dependence, sensitivity and fading of various safety glasses that are used as screen protectors of smartphones subjected to photon irradiation. Among the studied glasses, the HD Anti-Peep safety glass for iPhone has been found to exhibit a linear dose-response with a regression coefficient of 99% within the dose range of 2–10 Gy. Moreover, all the safety glasses showed independence with respect to photon energy of 6 MV and 10 MV. The TL glow curves of the samples showed a broad glow peak between 125 °C and 325 °C at 10 Gy. The TL kinetic parameters of the safety glasses were also studied by analyzing the glow curves using the peak shape and initial rise method. The geometric factor (μg) is found to be within the range of 0.43–0.53, which indicates the suitability of applying Chen's general-order formula to calculate the kinetic parameters such as activation energy, frequency factor and trap lifetime. The activation energy (E) and frequency factor (s) are found in the range of 0.31–0.54 eV and 4.55 × 103 to 2.12 × 106 s−1 respectively obtained via the peak shape method. The relatively long trap lifetime and observed thermoluminescence features indicate that the HD Anti-Peep safety glass offers a better option to estimate dose retrospectively to ensure the safety of human health.

Effect of Crystallization on Local Structure and Optical Properties of Glass with 12.5Li2O–50GeO2–37.5P2O5 Composition

Effect of Crystallization on Local Structure and Optical Properties of Glass with 12.5Li2O–50GeO2–37.5P2O5 Composition

Structure evolution of the silica glass under the vibration field through molecular dynamics simulations

AbstractSilica glass has found wide applications, including space shuttle windows, optical fibers, and deep ultraviolet light lens elements, due to its excellent optical, electrical, and mechanical properties. However, understandings of its structure change under the vibration field are limited in literature. In this work, the structure of silica glass and its behavior under the vibration field have been investigated through molecular dynamics simulations. The short and medium‐range structures, including coordination number, Qn species distribution, pair distribution function, and bond angle distribution, were analyzed. It was found that the overall and local structures of silica glass showed periodic changes under the vibration field. The root‐mean‐square displacements as well as the kinetic energies of the atoms in the system were further analyzed. The results show that there is a periodic transformation of kinetic and potential energies. In addition, the kinetic energy decreases and is converted into the thermal energy during the vibration, which is confirmed by the increase of the system temperature. This can explain the thermoelastic loss mechanism in energy dissipation from literature. This work reveals the structure evolution and energy change of glass under the vibration field from atomistic level, which provides important understandings for related researches.

Physical, optical, thermal, structural and mechanical properties of alkaline earth borate glasses

Binary alkaline earth borate glasses were synthesized via the melt quenching technique. The density and molar volume of the resultant glasses were determined experimentally. The glass optical basicity has been found to increase with the glass polarizability. The optical properties of the glasses were comprehensively analyzed, revealing a shift in the cutoff wavelength towards longer wavelengths with increasing glass optical basicity. Additionally, the optical band gap (Eg) was estimated. Structural investigations unveiled an increase in the abundance of BO4 units as the glass optical basicity increased. Furthermore, the glass transition temperature was observed to decrease with decreasing cation field strength. Glass packing density and B2O3 packing factor were calculated to assess structural variations. The longitudinal and shear velocities were determined using the pulse echo technique, providing insights into the elastic moduli of the glasses. The Makishima and Mackenzie approach was employed to predict the elastic moduli, yielding results in good agreement with experimental data. This comprehensive analysis sheds light on the relationship between composition, structure, and mechanical properties of binary alkaline earth borate glasses, offering valuable insights for potential applications.

Investigation of the thermal conductivity of SiO2 glass using molecular dynamics simulations

AbstractA recent study showed that generating local crystalline paths within a glassy matrix provides only a moderate increase in thermal conductivity until the path fills most of the total volume. It was indicated that percolation theory governs the thermal conductivity in such crystalline‐implanted glass composites. In this study, we use computer simulations to investigate the effect of partial vitrification by breaking structural order of silica crystals by local vitrification. Such locally vitrified crystal structures are made by the bond‐transposition method, where the extent of vitrification can be tuned. Also, we test melt‐quenching of three SiO2 crystalline structures (α‐quartz, coesite, and stishovite) to make silica glasses with different densities. The cooling rates and pressures were varied during the melting process in order to obtain glass structures with varied degrees of order. Our results show that the thermal conductivity of silica glasses calculated using Green–Kubo relation decreases rapidly as soon as the crystallinity is disturbed by bond transition or generated local glassy phase. This implies the phonon mean free path rapidly shrinks with even a small number of scatterers, regardless of the original polymorph. Through the investigation of the pressure effect, a strong proportional relation between the thermal conductivity and the density is found among all silica samples. Such correlation can be accounted by assuming a constant integral term in the Green–Kubo relation without the volume scaling, which is reasonable based on a weak dependence of κV on the density of silica glass except with a slight increase at low quench pressures. We hypothesize that when the quench pressure increases moderately, an increase of characteristic ring size tends to generate a more flexible SiO2 structure which results more phonon scattering. Green–Kubo modal analysis further shows that the contribution from modes at low frequencies is suppressed when SiO2 is melt‐quenched at higher pressure and vice versa.

High thermal stability molybdenum-Boosted lithium tellurite glass for radiation shielding

A novel glass system was developed using the melt-quenching technique. The primary aim was to investigate molybdenum-rich compositions (MoO3 > Li2O), with the general formula (69–2x) TeO2–(31+x)–MoO3–xLi2O (where x = 0, 5, 10, and 15 mol%). The physical, structural, thermal, mechanical and radiation shielding properties were evaluated. The synthesized glasses were characterized through their densities, molar volumes, and oxygen packing density, which revealed that the density and molar volume decreased as the amount of Li2O and MoO3 increased in the glass structure, while the oxygen packing density increased as a function of both Li2O and MoO3. Raman spectroscopy was used to analyze the glass structure, which showed a superimposed reduction of all Te units due to the formation of Te–O–Mo and a coordination change from MoO4 to MoO6. The interplay between Li2O and MoO3 has a direct effect on the thermal stability of the glass and reveals that glasses with higher MoO3 content and lower Li2O content exhibit enhanced thermal stability. The mass attenuation coefficient for the synthesized systems varied from 37.07 to 32.38 cm2 g−1 at 0.015 MeV. The fast neutrons removal cross-section exhibits a range from 0.090 to 0.096 cm−1 across all samples, while the thermal neutrons cross section values lie within the interval of 1.22–8.16 cm−1. The glass sample with the highest concentration of TeO2 showed superior values of mass attenuation, and fast neutrons removal cross-section, along with the lowest values of half value layer and mean free path. Nevertheless, the addition of MoO3 and Li2O improved thermal stability and led to adequate radiation protection levels. The results indicate the significant potential of MoO3-rich tellurite materials for shielding against gamma-ray and neutron radiation.

The influence of raw material changes on gamut colour volume of a matt ceramic glaze

This study aims to investigate the relationship between digital printing colour performance and the raw materials used in a matt glaze. Inkjet technology has enhanced the decorative properties of ceramic tiles in production. Improving the colour perception of the glaze is possible by optimizing the raw materials in the glaze, which results in less ink usage and thus lower costs. Investigation of the colour performance of glazes is possible by determining the L* a* b* values of the colours as well as the gamut colour volumes. Colour of the samples were evaluated by spectrophotometer and i1 profiler. Gamut volume was calculated by 3D CIE chromaticity diagrams of ICC profiles. It was observed that the colour saturation was higher in the samples where the pigment was homogeneously distributed in the glaze microstructure. SiO2 particles not embedded in the glass structure observed in the glaze microstructure disrupt the colour intensity. The low sphere temperature value of the composition made with wollastonite enabled the SiO2 particles to be embedded in the glaze. When wollastonite was used instead of dolomite as the source of calcium oxide in mat glaze, the colour gamut volume reached its highest value (11262), consequently increasing colour saturation. Conversely, the lowest colour gamut volume (6475) was obtained when dolomite was used instead of wollastonite.

Enhanced mechanical and thermophysical properties of Mg2Ca, Al2Ca, and Al4Ca bulk metallic glasses in comparison to crystalline alloys for bone grafting applications: A molecular dynamics investigation

We investigate the glassy-state properties of Mg2Ca, Al2Ca, and Al4Ca from the grafting application viewpoint. We employed classical molecular dynamics to examine the phase transition, structural, thermodynamic, transport, and mechanical properties in the amorphous state. All properties suggest successful simulations of the glass phase at and below the glass transition temperature, ranging between 550 and 689 K for Mg2Ca, Al2Ca, and Al4Ca. Computed results are compared and discussed with the reported findings and known mechanical and thermal properties of the various parts of the human bones and biocomposites. The comparison establishes that the mechanical, thermal, and transport properties significantly improve in the glass phase compared to its crystalline alloy form. At 300 K, studied glasses have densities in close agreement with human bone density. Structural analysis and heat capacity show the second-order phase transition, verifying the formation of the glass structure. The targeted glasses exhibit excellent thermal conductivity and thermal diffusivity compared to other commonly used biocomposites for bone grafting. Furthermore, the simulated elastic properties, viz., the Poisson ratio, G/B ratio, Cauchy's pressure, and yield strength, are in close agreement with the mechanical properties of various parts of human bone. The predicted ductility nature, contrary to the brittle character of Mg2Ca, Al2Ca, and Al4Ca crystalline alloys, proves the superiority of the glassy form for the implant's functioning. The minimum enthalpy of formation and thermodynamic stability of studied compounds benefit the synthesis process; hence, we propose that the studied glasses are persuasive materials for experimental synthesis aimed at bone grating applications.

A method to assess the quality of additive manufacturing metal powders using the triboelectric charging concept

A new method to assess the quality of additive manufacturing (AM) metal powders using the triboelectric charging concept is demonstrated using CpTi, Ti6Al4V, AlSi10Mg, IN 738, and SS 316L powders. For each powder tested, the surface chemical composition was first analyzed using X-ray photoelectron spectroscopy (XPS) to determine the composition of the passivation layer. Some modifications to the current GranuCharge™ setup, developed by GranuTools™, were then performed by incorporating a flow rate measuring tool to assess how tribocharging is affected as a function of flow rate. Variations in the tribocharging response have been found with the flow rate of CpTi, AlSi10Mg and SS 316L powders. Moreover, results suggest that the tribocharging behavior might not be the same even with powders fabricated with the same passivation process. Finally, the compressed exponential model of Trachenko and Zaccone was used to reproduce the tribocharging behavior of the powders. The models were found to work best when the stretch constant β = 1.5, which is identical to the value found in other systems such as structural glasses, colloidal gels, entangled polymers, and supercooled liquids, which experience jamming when motion of individual particles become restricted, causing their motion to slow down.

On the structure and icosahedral interconnectivity in Tantalum monatomic glass produced under pressure

Proper processing of bulk metallic glasses (BMGs) under pressure is a promising approach to tailor their properties. However, to fully understand how pressure processing affect the final glass properties, a clearer understanding of how the pressure affects the structure of the glass at both short- and medium range levels is required. Accordingly, using molecular dynamics simulations, we study the effect of cooling under pressure on the local structure and the medium-range connectivity in a model Tantalum monatomic metallic glass. Crystalline grains form in the Ta sample with increasing the pressure under which the sample was cooled. These observations were confirmed by decreasing the fivefold symmetry with increasing pressure. The connectivity type between the perfect icosahedra was determined and showed that when cooled under pressure, intercross sharing is favored in the higher pressure. This work gives insights into understanding local structural changes induced by the pressure in metallic glasses.