Glass Structure Research Articles

Ultra-Broadband Plasmon Resonance in Gold Nanoparticles Precipitated in ZnO-Al2O3-SiO2 Glass

Optical materials with a tunable localized surface plasmon resonance (LSPR) are of great interest for applications in photonics and optoelectronics. In the present study, we explored the potential of generating an LSPR band with an ultra-broad range of over 1000 nm in gold nanoparticles (NPs), precipitated through a thermal treatment in ZnO-Al2O3-SiO2 glass. Using optical absorption spectroscopy, we demonstrated that the LSPR band’s position and shape can be finely controlled by varying the thermal treatment route. Comprehensive methods including Raman spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy were used to study the glass structure, while computational approaches were used for the theoretical description of the absorption spectra. The obtained results allowed us to suggest a scenario responsible for an abnormal LSPR band broadening that includes a possible interparticle plasmonic coupling effect taking place during the liquid–liquid phase separation of the heat-treated glass. The formation of gold NPs with an ultra-broad LSPR band in glasses holds promise for sensitizing rare earth ion luminescence for new photonics devices.

A Short Review of Advances in MOF Glass Membranes for Gas Adsorption and Separation.

The phenomenon of melting in metal-organic frameworks (MOFs) has recently garnered attention. Crystalline MOF materials can be transformed into an amorphous glassy state through melt-quenching treatment. The resulting MOF glass structure eliminates grain boundaries and retains short-range order while exhibiting long-range disorder. Based on these properties, it emerges as a promising candidate for high-performance separation membranes. MOF glass membranes exhibit permanent and accessible porosity, allowing for selective adsorption of different gas species. This review summarizes the melting mechanism of MOFs and explores the impact of ligands and metal ions on glassy MOFs. Additionally, it presents an analysis of the diverse classes of MOF glass composites, outlining their structures and properties, which are conducive to gas adsorption and separation. The absence of inter-crystalline defects in the structures, coupled with their distinctive mechanical properties, renders them highly promising for industrial gas separation applications. Furthermore, this review provides a summary of recent research on MOF glass composite membranes for gas adsorption and separation. It also addresses the challenges associated with membrane production and suggests future research directions.

Correlation of thermal and electrical properties of silver germanophosphate glasses with their structural analysis by Raman and NMR spectroscopy

In present study glasses of the system Ag2O-GeO2-P2O5 were studied in the compositional series (50−x)Ag2O-xGeO2-50P2O5 with x = 0−40 mol%. Ag2O substitution by GeO2 results in a significant increase of both glass transition temperature, Tg, and crystallization temperature, Tc, up to 628 °C (Tg) and 851 °C (Tc) at x = 40 mol% GeO2. The glass structure was investigated from the analysis of 31P MAS NMR and Raman spectra. Both methods show transformation of phosphate glass network formed mainly by Q2 units to germanate-phosphate network formed by Q1xGe and Q21Ge phosphate units and germanate units. Raman spectra, in addition, reveal evolution of P‒O‒P linkages to P‒O‒Ge and Ge‒O‒Ge linkages through the glass series. DC conductivity trend upon GeO2 addition showed non-monotonic behaviour, which is related to structural changes in the glass-network.

Advances in laser‐based manufacturing techniques for specialty optical fiber

AbstractAs demand for customized specialty fibers grows, standardized production methods face challenges. This article reviews industry standards and discusses potentially disruptive techniques that enable rapid prototyping and fabrication of optical fiber devices. Furthermore, we showcase laser powder deposition's (LPD) potential for additive manufacturing (AM) of customized glass structures. In the case of, for example, fiber preforms, although the feasible size is smaller than the industry standard, utilizing laser‐based manufacturing techniques for a small batch production presents an attractive avenue for rapid prototyping and expedites material and design optimization. In the realm of AM of glass, LPD offers numerous benefits, including minimal shrinkage, high densification, and the ability to tailor glass composition to achieve desired optical properties. The article reviews the latest achievements and highlights future directions in this technology.

Achieving High-Temperature Stable Structural Color through Nanostructuring in Polymer-Derived Ceramics.

Structural colors offer a myriad of advantages over conventional pigment-based colors, which often rely on toxic chemical substances that are prone to UV degradation. To take advantage of these benefits in demanding environments, there is growing interest in producing structural colors from ceramics. Polymer-derived ceramics (PDCs) emerge as a compelling choice, presenting two distinct advantages: their enhanced shape ability in their polymeric state associated with impressive temperature resistance once converted to ceramics. This study pioneers the fabrication of noniridescent structural colors from silicon oxycarbide (SiOC) PDC, enabled by the nanostructuring of an inverse photonic glass within the PDC material. This design, a functionally graded material with an inverse photonic glass (FGM-PhG) structure, leverages the innate light-absorbing properties of SiOC, yielding a vivid structural color that maintains its saturation even in white surroundings. This study elucidates the process-structure-properties relationship for the obtained structural colors by investigating each layer of the functionally graded material (FGM) in a stepwise coating deposition process. To further emphasize the exceptional processing flexibility of PDCs, the three-step process is later transferred to an additive manufacturing approach. Finally, the FGM-PhG structural colors are demonstrated to have remarkable thermal stability up to 1000 °C for 100 h, possibly making them the most thermally stable ceramic structural colors to date.

Influence of Chemical Composition and Structure on the Cooperative Fluctuation in Supercooled Glass-Forming Liquids.

The kinetics of the glass transition and the characteristic size of the fluctuating spatio-temporal domains in supercooled glass-forming liquids, i.e., the Cooperatively Rearranging Regions (CRR), were measured upon cooling over a broad range of cooling rates using Differential Scanning Calorimetry (DSC) and chip-based Fast Scanning Calorimetry (FSC). The investigations were conducted on a selection of fragile glass formers (fragility indices between 80 and 140), with a large variance in the atomic or molecular structure but comparable thermal glass transition temperatures Tg, with the aim of evaluating the influence of chemical composition and structure on the CRR size and the associated temperature fluctuation. The selected materials are two polymers (poly(vinyl acetate) (PVAc), poly(lactic acid) (PLA)) as well as the simplest chalcogenide glass-former (selenium). It turned out that the CRR size plotted against the reduced temperature T/Tg follows the same trend, irrespective of the considered glass-former.

From structure to luminescence investigation of B2O3-GeO2-BaO-ZnO glass doped with Dy3+

This study describes the preparation of Dy3+ doped B2O3-GeO2-BaO-ZnO (BGBZ) glass using a high temperature melting technique. By means of excitation and emission spectroscopy, it was determined that the glass sample with 25 mol% BaO content had the maximum luminous intensity. The internal structure of the glass was investigated using FT-IR spectroscopy, absorption spectrum testing, and J-O theoretical analysis in order to investigate the principle. The FT-IR spectrum revealed the coexistence of [BO3], [BO4], [GeO4], and [GeO6] coordination polyhedra. The Ω2 value reaching its maximum when the BaO content reached 25mol%, indicating the highest degree of asymmetry in the glass structure at that time. After analyzing the impact of BaO content on the glass structure, it was investigated how the concentration of Dy2O3 doping affected the glass's optical characteristics and radiation performance. By calculating the CIE of glass samples, it was found that the CCT value of glass sample 1.25Dy was 6735 K, suggesting that the produced glass may find use in the w-LED commercial industry. The 0.50Dy glass sample was calculated to have a high σse (8.47×10−22 cm2) from the emission spectral data, suggesting that the prepared glass sample may also be suitable for lasers.

Experimental radiation shielding, mechanical and optical properties for borosilicate glass system: Role of varying SrO

Borosilicate glass is one of the famous glasses used in labs and kitchenware since its thermal expansion is so low. This research synthesized a new group of borosilicate glass to study its mechanical, optical, and radiation shielding properties. The experimental shielding setup was set to explore the glass performance in the radiation shielding field. The results were compared with the XCOM data to check validity. The optical properties were determined using absorption spectra for glass samples. At the same time, the mechanical properties were assessed theoretically to give an impression of the glass structure. The radiation shielding experimental setup was validated with a relative difference of 9.8066% between practical and theoretical findings. Meanwhile, adding SrO instead of B2O3 increased the radiation shielding features. The mass attenuation coefficient values at 0.184 MeV rose from 0.1448 to 0.1474 cm2/g with the addition of SrO. The mechanical and optical parameters showed variation in results when SrO was added. For example, the band gap values are 3.547, 3.485, 3.675, and 3.527 eV for STBS15, STBS20, STBS25, and STBS30, respectively. The Urbach energy results are 0.183, 0.182, 0.180, and 0.173 eV for STBS15, STBS20, STBS25, and STBS30, respectively. At the same time, the Young modulus results are 94.071, 88.880, 89.207, and 86.035 GPa for STBS15, STBS20, STBS25, and STBS30, respectively. The Poisson ratio ranged from 0.284 to 0.278 for STBS15 and STBS30. The adding SrO reduced the hardness from 5.260 to 4.966 GPa for STBS15 and STBS30. Finally, the results indicate the ability to use current glasses in the radiation shielding applications.

Judd-ofelt analysis and luminescent properties of the Dy3+-doped borosilicate glass

B2O3-SiO2-WO3-Ga2O3 glasses doped with Dy3+ were synthesized using the high-temperature melting method. The effects of different B2O3/SiO2 ratios, different Dy3+ ions doping concentrations, and alkali metal oxides on the glass structure and optical properties were investigated through the test methods of X-ray diffraction, differential scanning calorimetry, Fourier infrared spectra, and photoluminescence spectra. The oscillator strength and intensity parameters were determined using Judd-Ofelt theory, and the optical band gap for both indirect and direct allowed transitions were calculated. The glasses exhibited optimal luminous performance when the B2O3/SiO2 ratio was 50:33, Dy2O3 doping concentration was 0.5 mol%, and K2O concentration was 4 mol%, excited by a wavelength of 388 nm. The CIE coordinates falling within the white light region suggest the potential application of these glasses in white solid-state lighting.

Effects of P2O5 content on the structure, stress distribution and vickers hardness of Na2O-MgO-Al2O3-SiO2 glasses with chemical strengthening treatments

In this work, effects of P2O5 content on the structure, stress distribution and vickers hardness of alkali aluminosilicate glasses with different chemical strengthening treatments were investigated. The results showed that the addition of P2O5 increased the degree of polymerization for glass network. The coefficient of thermal expansion, glass transition temperature and density of the parent glasses were all decreased. Meanwhile, the molar volume of the samples increased. The chemical strengthening experiments revealed that increasing P2O5 content promoted the diffusion of K+ ions, which resulted in an increase in the depth of stress layer. However, surface compressive stress of the glasses decreased with P2O5 content increasing, mainly attributed to stress relaxation of the glass structure. After chemical strengthening treatments at 370 °C and 390 °C respectively, the vickers hardness of the glasses decreased with the increase of P2O5, while an opposite trend was observed at 410 °C.

Evolution of local structures in alkali-borate glasses

We analyze the dependence of the relative proportion of various characteristic clusters in binary alkali borate glasses on modifier concentration x. Pure B2O3 glass contains, according to various estimates, from 75% up to 85% of boron atoms inside boroxol rings, wih the remaining boron atoms in between, linking the boroxol rings via oxygen bonds. The addition of Na2O modifier creates four-coordinated borons, but the resulting network glass remains totally connected. We study local transformations that lead to the creation of new configurations such as tetraborates, pentaborates, diborates, etc., and set forth a nonlinear differential system similar to the Lotka–Volterra equations. The resulting density curves of various local configurations as functions of x are obtained. Then the average rigidity is evaluated, enabling us to compute the glass transition temperature Tg(x) for a given value of x.

Effect of B2O3 and Basic Oxides on Network Structure and Chemical Stability of Borosilicate Glass

Glass properties play crucial roles in ensuring the safety and reliability of electronic packaging. However, challenges, such as thermal expansion and resistance to acid corrosion, pose long-term service difficulties. This study investigated the impact of the microstructure on acid resistance by adjusting the glass composition. A glass material with excellent acid resistance was obtained by achieving a similar coefficient of thermal expansion to tantalum; it exhibited a weight loss rate of less than 0.03% when submerged in 38% sulfuric acid at 85 °C for 200 h. Theoretically, this glass can be used to seal wet Ta electrolytic capacitors. Differential scanning calorimetry (DSC) was used to analyze the glass transition temperature and thermal stability of borosilicate glasses. X-ray diffractometry (XRD), scanning electron microscopy (SEM), and Raman spectroscopy were used to study the microstructure of the amorphous phase of the borosilicate glass, which revealed a close relationship between the degree of network phase separation in the borosilicate glass and the degree of polymerization (isomorphic polyhedron value, IP) of the glass matrix. The IP value decreased from 3.82 to 1.98 with an increasing degree of phase separation. Boron transitions from [BO4] to [BO3] within the glass network structure with increasing boron oxide content, which diminishes the availability of free oxygen provided by alkaline oxide, resulting in a lower acid resistance. Notably, the glass exhibited optimal acid resistance at boron trioxide and mixed alkaline oxide contents of 15% and 6%, respectively. Raman experiments revealed how the distributions of various bridging oxygen atoms (Qn) affect the structural phase separation of the glass network. Additionally, Raman spectroscopy revealed the depolymerization of Q4 into Q3, thereby promoting high-temperature phase separation and highlighting the unique advantages of Raman spectroscopy for phase recognition.

Effect of compression temperature on the structure and properties of hot compressed sodium borosilicate glasses from molecular dynamics simulations

Applying pressure during glass formation or annealing is an effective method to modify the properties of oxide glasses. The effect of compression temperature on the structure and properties of a sodium borosilicate glass has been investigated using molecular dynamics simulations. The connection between macroscopic properties (density and elastic moduli) and microscopic structures (short- and medium-range order) was investigated. Young’s modulus increased with the compression temperature and then reached a plateau at temperatures close to the glass transition temperature. The modulus increase was found to correlate linearly with glass density change. Correlations with structural changes, such as fraction of four-fold coordinated boron, oxygen triclusters, sodium ion coordination number and the Na–O and Na–Na distances were studied. The results suggest that the pressure-induced transformation from three-fold to four-fold coordinated boron was achieved through the formation of oxygen triclusters, which is different from the commonly observed mechanism involving nonbridging oxygen during the boron coordination change. In addition, the linear correlation between sodium coordination number and glass density suggests that change of sodium ion local environment and redistribution of sodium ions also play an important role in the property behaviour during pressure quenching of the glasses.

Fast, Precise, High Contrast Laser Writing for Photonic Chips with Phase Aberrations

AbstractIntegrated photonic chips have significant potential in telecommunications, classic computing, quantum systems, and topological photonics. Direct laser writing offers unique capability for creating three‐dimensional photonic devices in an optical glass chip with quick prototyping. However, it is a challenge for existing laser writing schemes to create index‐modified structures in glass that precisely match the laser focal shape while also achieving high refractive index contrasts and high scanning speeds. Here, we introduce a refractive index modification scheme that combines the advantages of non‐thermal and thermal regime fabrication methods. We also propose a waveguide formation model that is verified through a thorough study on the effects of phase aberrations. The presented new photonic chip fabrication scheme uses a novel focal intensity distribution, where pulse energy is relocated to the bottom of a laser focus by manipulating primary and higher order spherical aberrations. The technique can produce index modifications with high scanning speed (can be 20 mm/s or higher), high index contrast (ranging from 0.009 to 0.021), and high precision to fabricate with arbitrary cross‐sections. This method has potential to expand the capabilities of photonic chips in applications that require small‐scale, high precision, or high contrast refractive index control.

Topological constraint model of modified telluro‐vanadate glasses

AbstractTopological constraint theory has emerged as a rapid, predictive method to quantify the relationship between structural rigidity and glass properties. Understanding the structure of telluro‐vanadate (TeO2–V2O5) glasses has remained difficult owing to their complex mixture of structural units. Here, we propose a topological model that accurately captures the glass structure and can be used to predict properties such as glass transition temperature and hardness. The experimentally obtained properties are in agreement with predicted properties by the model suggesting that this simplified structural model accurately describes the V2O5–TeO2 structure.

Design and Tests of Structural Post-Tensioned Glass T-Beams

Glass manifests superior properties with high strength and transparency although it may not be considered as a commonly used structural material. This study targets to improve the structural performance of glass by post-tensioning; a series of T-shaped glass beams are tested to develop a proper and safe design. Traditionally, glass is widely used in buildings as windows where its brittleness and strength capacity are not significant. Architects prefer to use glass in the structural field because of aesthetics, recyclability, and transparency. Although there is more demand for the usage of glass as a structural material, a common fear of its brittle nature and lack of research about its structural behavior have mostly hindered it. Since glass is a brittle material and has high compressive strength in the order of 400 to 800 MPa and lower tensile strength (40 to 120 MPa), post-tensioning to target distributed loads is investigated to increase its fracture capacity and even obtain a post-cracking ductile behavior. In this study, several material tests are conducted to confirm the theoretical mechanical properties of glass. After obtaining the bending and compressive strength of the glass, Finite Element Models (FEMs) of the T-beams were generated and analytical hand calculations were conducted. The tests of T-shaped annealed (float) and tempered (toughened) glass beams with and without post-tensioning were conducted. The results of the experiments were compared with the analytical hand calculations and FEM results. A favorable outcome of this study is that float glass’ post cracking strength has been drastically increased and a ductile post-cracking performance is obtained. Tempered glass has a brittle response but with much higher strength, with about 4 times the capacity of annealed glass T-beams

Modeling manganese lithium borate-based glass using a combination of X-ray absorption spectroscopy and computer simulations

This work presents a comprehensive study on the structural analysis of manganese lithium borate-based glass, which is of significant interest in energy storage device technology. The glass, denoted as xMnO2-(1-x)(Li2O–2B2O3), with varying MnO2 compositions (x = 0.2, 0.25, and 0.3), was thoroughly investigated through a combination of X-ray Absorption Spectroscopy (XAS), Molecular Dynamics (MD) simulations, and Reverse Monte Carlo (RMC) refinement to delve into its atomic-level structure. Insights into the coordination environments were obtained from XAS results, while MD simulations revealed the structural characteristics and dynamics. RMC refinement facilitated the creation of realistic glass structures by fitting experimental constraints, establishing a solid foundation for simulated structures validated against experimental findings. This study also determined an optimal Mn2+/Mn3+ ratio of 60:40, which is instrumental in enhancing the electrochemical performance of the material, thereby contributing to a better understanding of the structural and electronic properties of the manganese lithium borate-based glass. These findings have significant implications for energy storage applications and offer directions for further studies on this interesting glass system.

Engineering application study of high-performance aluminum alloy 6A13-T6

To address the application challenges of the novel high-strength aluminum alloy material 6A13-T6 in engineering, experimental and numerical simulation studies were conducted. Firstly, material tensile tests, axial compression tests, and pure bending tests were conducted, and the applicability of the specification was evaluated. Subsequently, finite element models were employed to analyze the overall mechanical performance and economic indicators of three typical engineering structures (grid shells, grid trusses, and glass curtain walls) based on the test results. The findings indicate that 6A13-T6 exhibits a non-proportional yield strength (f0.2) of 340 MPa, an ultimate strength of 352 MPa, and a post-necking elongation of 14.5%. Design calculations for axially compressed and flexural members made of 6A13-T6 high-strength aluminum alloy can be conservatively carried out following Chinese design specification. The use of 6A13-T6 aluminum alloy can reduce material consumption in structures, with a maximum reduction of up to 29% compared to other commonly used aluminum alloys and up to 72% compared to common steel materials. Therefore, the new high-strength aluminum alloy 6A13-T6 has obvious engineering application value and has been used in a hotel curtain wall project.

Insights into Lithium Sulfide Glass Electrolyte Structures and Ionic Conductivity via Machine Learning Force Field Simulations.

Sulfide-based solid electrolytes (SEs) are important for advancing all-solid-state batteries (ASSBs), primarily due to their high ionic conductivities and robust mechanical stability. Glassy SEs (GSEs) comprising mixed Si and P glass formers are particularly promising for their synthesis process and their ability to prevent lithium dendrite growth. However, to date, the complexity of their glassy structures hinders a complete understanding of the relationships between their structures and properties. This study introduces a new machine learning force field (ML-FF) tailored for lithium sulfide-based GSEs, enabling the exploration of their structural characteristics, mechanical properties, and lithium ionic conductivities. Using molecular dynamic (MD) simulations with this ML-FF, we explore the glass structures in varying compositions, including binary Li2S-SiS2 and Li2S-P2S5 as well as ternary Li2S-SiS2-P2S5. Our simulations yielded consistent results in terms of density, elastic modulus, radial distribution functions, and neutron structure factors compared to DFT and experimental work. Our findings reveal distinct local environments for Si and P within these glasses, with most Si atoms in edge-sharing configurations in Li2S-SiS2 and a mix of corner- and edge-sharing tetrahedra in the ternary Li2S-SiS2-P2S5 composition. For lithium ionic conductivity at 300 K, the 50Li2S-50SiS2 glass displayed the lowest conductivity at 2.1 mS/cm, while the 75Li2S-25P2S5 composition exhibited the highest conductivity at 3.6 mS/cm. The ternary glass showed a conductivity of 2.6 mS/cm, sitting between the two. Moreover, an in-depth analysis of lithium ion diffusion over the MD trajectory in the ternary glass demonstrated a significant correlation between diffusion pathways and the rotational dynamics of nearby SiS4 or PS4 tetrahedra. The ML-FF developed in this study provides an important tool for exploring a broad spectrum of solid-state and mixed former sulfide-based electrolytes.

Exploring the Impact of Copper Oxide Substitution on Structure, Morphology, Bioactivity, and Electrical Properties of 45S5 Bioglass®.

In recent decades, the requirements for implantable medical devices have increased, but the risks of implant rejection still exist. These issues are primarily associated with poor osseointegration, leading to biofilm formation on the implant surface. This study focuses on addressing these issues by developing a biomaterial for implant coatings. 45S5 bioglass® has been widely used in tissue engineering due to its ability to form a hydroxyapatite layer, ensuring a strong bond between the hard tissue and the bioglass. In this context, 45S5 bioglasses®, modified by the incorporation of different amounts of copper oxide, from 0 to 8 mol%, were synthesized by the melt-quenching technique. The incorporation of Cu ions did not show a significant change in the glass structure. Since the bioglass exhibited the capacity for being polarized, thereby promoting the osseointegration effectiveness, the electrical properties of the prepared samples were studied using the impedance spectroscopy method, in the frequency range of 102-106 Hz and temperature range of 200-400 K. The effects of CuO on charge transport mobility were investigated. Additionally, the bioactivity of the modified bioglasses was evaluated through immersion tests in simulated body fluid. The results revealed the initiation of a Ca-P-rich layer formation on the surface within 24 h, indicating the potential of the bioglasses to enhance the bone regeneration process.