International Journal of Applied Glass Science最新文献

Glass through-holes are essential for wafer-level packaging of microelectromechanical systems (MEMS) devices and are often fabricated through wet bulk micromachining. For efficient through-hole fabrication, there is a need for the development of cost-effective masking layers and faster etching processes. This work presents an economical method for fabricating through-holes of various dimensions in 500 µm-thick Borofloat glass wafers with a relatively high etch rate using wet bulk micromachining. The process employs wet isotropic etching in 25% and 30% hydrofluoric acid (HF), utilizing a masking layer of sputter-deposited Cr thin film and spin-coated positive photoresist. The masking layer revealed strong adhesion to the wafers during the entire etching process, enabling the fabrication of through-holes with sharp edges. Additionally, the masking layer delivered excellent resistance to both HF concentrations, establishing effective protection, and subsequently resulting in minimal defects on the wafer surface. Through-holes are fabricated in 190 min using 25% HF and in 150 min using 30% HF, with the latter facilitating comparatively faster fabrication due to its higher HF concentration. The present work demonstrates the best output in terms of faster etching time for through-holes fabrication in glass wafers using a Cr thin film combined with a photoresist as a masking layer.

Molten calcium–magnesium–aluminosilicate (CMAS) containing debris is a leading threat to hot-section components in air-ingesting turbine engines. This study investigated common natural-forming and coating-derived oxide additions to CMXAS glasses—where X denotes a fifth oxide constituent. Glass property relationships are elucidated by cation size effects and allow inferences to glass structure to be made. Iron oxide content, Group IV metal, and rare-earth metal cations—including one dual cation addition (Y³⁺ and Yb³⁺)—effects on CMAS viscosity, coefficient of thermal expansion (CTE), softening temperature, and glass transition temperature were explored. The baseline material, nominally a 33 CaO–9 MgO–13 AlO_1.5–45 SiO₂ (single cation oxide mol%) CMAS, was synthesized from constituent oxide powders. Natural-forming additions consistently operated as network modifiers. However, coating-derived additions behaving as network modifiers in the molten liquid state were found to behave as network formers in the condensed amorphous state. Fe³⁺ additions were shown to have the greatest effect of all additions on glass properties, exhibiting the greatest propensity for CMAS attack. Trends observed between dilatometric CMXAS glass properties allow for CMXAS properties to be inferred should one property (CTE, T_d, T_g) be known. Coating performance should consider the effect of coating constituent on CMAS viscosity and CTE, dissolution, and precipitation behaviors.

A new technique, termed the stirred-reactor coupon analysis (SRCA) method, has been developed to measure the rate of glass dissolution in forward-rate conditions. Monolithic glass coupons are partially masked with an inert material before placement in a large volume of well-mixed solution with known chemistry and temperature for a predetermined duration. After the test, the mask is removed, and the difference in step height between the protected area and the exposed corroded portions of the sample coupon is measured to determine the extent of glass dissolution. The step height is converted to a rate measurement using the test duration and glass density. Test parameters such as sample surface preparation and test duration were evaluated to determine their effects on the measured rates. Additionally, results from an interlaboratory study (ILS) consisting of 12 laboratories from 11 different institutions are presented, where each laboratory performed 12 independent tests. When removing experimental outlier data, the 95% reproducibility limits for the SRCA method has no statistical difference with previously published standardized test methods used to determine the forward rate of glass dissolution. Overall, this paper describes steps necessary to perform the test method and provides the statistical calculations to evaluate test accuracy.

Silica glass (SG) is a highly versatile material used in optics, electronics, construction, and medicine due to its transparency and mechanical properties. However, enhancing its performance poses scientific challenges, especially in reinforcing it while preserving these properties and understanding its deformation under stress. This study investigates the effect of gold nanoparticles (AuNPs) on the mechanical response of SG material. AuNPs were nucleated into high-purity SG using a 3MV Tandem Accelerator Pelletron, followed by thermal annealing at 600°C in an H₂ + N₂ atmosphere. High-resolution transmission electron microscopy (HRTEM) revealed a Gaussian distribution of AuNPs at a depth of ∼450 nm. Nanoindentation tests indicated minor variations in hardness (1.5%) and reduced elastic modulus (4.4%) with AuNP incorporation. Scratch tests demonstrated that the mechanical integrity of the AuNPs/SG sample was preserved when deformation remained below the determined fracture load of SG, although it exhibited a slightly higher coefficient of friction. Finite element analysis provided insights into the strain behavior within the AuNP zone, confirming how AuNPs distribute stress within the SG matrix.

This paper reports the preparation and characterization of LaF₃-based glass–ceramic (GC) optical fibers codoped with Er³⁺ and Yb³⁺ ions, using the rod-in-tube method with Duran glass as cladding. Structural analysis, including x-ray diffraction and transmission electron microscopy, confirmed the presence of LaF₃ nanocrystals in the core, with sizes ranging from 8 to 10 nm, slightly smaller than those observed in bulk samples due to the higher cooling rate during fiber drawing. Optical measurements showed transmission losses of 13 dB/m for the GC fibers after heat treatment at 660°C for 40 h. Upconversion (UC) emissions were observed in the green (²H_11/2, ⁴S_3/2 → ⁴I_15/2), red (⁴F_9/2 → ⁴I_15/2), and blue (²H_9/2 → ⁴I_15/2) regions upon excitation at 980 nm. The dependence of UC emission on pump power showed a near linear dependence, which can be explained by saturation effects in the intermediate energy states and indicates that the UC process is driven by energy transfer from Yb³⁺ to Er³⁺ ions. These results demonstrate the potential of these fibers for advanced optical applications, including telecommunication, sensors and laser technologies.

Topological constraint theory has enabled the successful prediction of glass properties over a wide range of compositions. In this study, a topological constraint model is constructed for alkaline earth vanadate glasses based on experimental data. The change in vanadate structural units from VO₅ to VO₄ was modeled as a function of alkaline earth content and related to thermal and mechanical properties. The model covers both high- and low-temperature properties to probe the temperature dependence of constraint rigidity for each constituent of the glass network. The model is changed to describe anomalies in magnesium sites potentially implying that magnesium can form locally rigid structures. Furthermore, the traditional understanding of vanadate glass structure is compared to recent results concluding that the terminal oxygen must exist as a part of the VO₄ units. Results for the model explain that bridging oxygen constraints are the main contributors to network rigidity in both low- and high-temperature regimes. Vanadate glass networks are highly connected even with the introduction of modifier species, which introduce their own bond constraints. Corroboration between experimental data and the topological constraint model illustrates the role of alkaline earth oxides in the glass network.

This work demonstrates the capability to crystallize YAG via femtosecond pulsed laser. Challenges in using melt-quench glass are shown to restrict glass composition and have not yielded YAG via femtosecond laser crystallization. An alternative glass-making technique was used to fabricate a range of compositions not otherwise possible. Glasses of YAG with added silica in the range of 0–20 mol% were tested under the laser to explore the allowable deviation from stoichiometric YAG. Raman spectroscopy and Electron backscatter diffraction indicated successful fabrication of YAG, and usage of combined excitation emission spectroscopy (CEES) allowed probing of erbium doped compositions.

CsPbBr₃ perovskite nanocrystals (PNCs) were successfully embedded in a borosilicate glass matrix for a robust green color converter, and its photoluminescence quantum yield (PLQY) was optimized by varying glass composition and heat treatment conditions. A high PLQY of up to 68% was obtained under 450 nm excitation by adjusting ZnO and Al₂O₃ content and by incorporating Ga₂O₃. The formation of PNCs was confirmed by X-ray diffraction (XRD) and transmission electron microscope (TEM), while the effect of compositional variation was investigated by nuclear magnetic resonance (NMR), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Time-resolved photo-luminescence (TRPL) also examined the effect of the composition and the heat treatment on the PLQY. Thermal, chemical, and photonic stabilities of the CsPbBr₃ PNC embedded glass (PNEG) were examined to show its robustness for practical applications. A white light-emitting device consisting of CsPbBr₃ PNEG and commercial red phosphor (K₂SiF₆:Mn⁴⁺) with an InGaN blue LED chip was composed and achieved a wide color gamut reaching up to 131% of the NTSC standard, successfully demonstrating its practical feasibility as a color converter for display applications.

This study investigates the effects of chromium concentration and redox on simulated high-level waste (HLW) borosilicate glass properties for high-chromium Hanford wastes. Thirty glasses with target 1 ≤ Cr₂O₃ ≤ 2.5 wt% were fabricated and analyzed. The Cr redox ratios were measured using K-edge X-ray absorption near edge structure along with properties of interest to vitrification of Hanford HLW: crystal formation after centerline canister cooling, crystallinity as a function of temperature, viscosity, electrical conductivity, toxic characteristic leaching procedure and product consistency test (PCT) responses, and SO₃ solubility. Only Cr(III) and Cr(VI) were identified in the test glasses, and their ratio was found to be largely correlated to optical basicity. Cr redox appeared to have a significant impact on most of the properties, except for PCT. Most properties were affected differently by Cr(III) than by Cr(VI). These effects were quantified and rationalized based on the previously studied bonding nature of the two primary oxidation states.

Ultrafast laser irradiation of glass enables highly localized structural transformations within the material's bulk, unlocking diverse applications in photonics, data storage, and microfabrication. Here, we provide a concise yet comprehensive overview of the main types of femtosecond laser-induced modifications in silica-based glasses (Types I, II, III, X, and related crystalline transformations), highlighting their distinct features and underlying thermal- and pressure-driven mechanisms. This review offers a current state-of-the-art perspective on various modifications, while also presenting new nanoscale insights through advanced scattering scanning near-field optical microscopy and nano-Fourier transform infrared spectroscopy, discussing the densification mechanisms behind. Finally, we outline broader perspectives, from fundamental research directions to industry developments, to inspire future advances in next-generation optical technologies.