Aluminosilicate Glass Research Articles

90Y]Yttria Alumino Silicate Glass Microspheres: A Biosimilar Formulation to "TheraSphere" for Cost-Effective Treatment of Liver Cancer.

Background: Selective internal radiation therapy (SIRT) using a suitable β--emitting radionuclide is a promising treatment modality for unresectable liver carcinoma. Yttrium-90 (90Y) [T1/2 = 64.2 h, Eβ(max) = 2.28 MeV, no detectable γ-photon] is the most preferred radioisotope for SIRT owing to its favorable decay characteristics. Objective: The present study describes indigenous development and evaluation of intrinsically radiolabeled [90Y]yttria alumino silicate ([90Y]YAS) glass microsphere, a formulation biosimilar to "TheraSphere" (commercially available, U.S. FDA-approved formulation), for SIRT of unresectable liver carcinoma in human patients. Methods: YAS glass microspheres of composition 40Y2O3-20Al2O3-40SiO2 (w/w) and diameter ranging between 20 and 36 μm were synthesized with almost 100% conversion efficiency and >99% sphericity. Intrinsically labeled [90Y]YAS glass microspheres were produced by thermal neutron irradiation of cold YAS glass microspheres in a research reactor. Subsequent to in vitro evaluations and in vivo studies in healthy Wistar rats, customized doses of [90Y]YAS glass microspheres were administered in human patients. Results: [90Y]YAS glass microspheres were produced with 137.7 ± 8.6 MBq/mg YAS glass (∼6800 Bq per microsphere) specific activity and 99.94% ± 0.02% radionuclidic purity at the end of irradiation. The formulation exhibited excellent in vitro stability in human serum and showed >97% retention in the liver up to 7 d post-administration when biodistribution studies were carried out in healthy Wistar rats. Yttrium-90 positron emission tomography scans recorded at different time points post-administration of customized dose of [90Y]YAS glass microspheres in human patients showed near-quantitative retention of the formulation in the injected lobe. Conclusions: The study confirmed the suitability of indigenously prepared [90Y]YAS glass microspheres for clinical use in the treatment of unresectable hepatocellular carcinoma.

The effect of nucleating temperature on the crystallization, phase formation and properties of lithium aluminum silicate (LAS) glass-ceramics

To study the influence of the nucleation mechanism in lithium aluminosilicate glass, a composition similar to commercially produced glass was used. The glass-ceramics was obtained as a result of two-stage heat treatment, differing in the nucleation temperature and coinciding in the temperature and time of crystal growth. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) were used to study the formed nanocrystals. It was shown that the change of nucleation temperature in the glass transition interval Tg ±15 °C significantly affects the coefficient of thermal expansion, which is due to the formation of a different number of nanocrystals of the general composition LixAlxSi1-xO2 with x = 0.33 with the size less than 50 nm.

Radiation Shielding Properties of Aluminosilicate Glass Systems using Phy-X Software

In this work, we studied the radiation shielding properties of aluminosilicate glasses with constant SiO2 content. By applying Phy-X software, we calculated different radiation attenuation factors for the chosen glasses. The linear attenuation coefficient (LAC) for the chosen CaO–Al2O3–SiO2 glass systems showed an exponential decrease as the energy changes from 0.015 to 15 MeV. For the glass with composition of 35CaO-5Al2O3-60SiO2, the LAC decreases from 29.80 to 1.279 cm-1 between 0.015 and 0.05 MeV. The LAC decreases with the increase in the Al2O3 content. The minimum LAC is found for the glass with the composition of 20CaO-20Al2O3-60SiO2. The effective atomic number (Zeff) was reported, and we found that the highest Zeff is occurred at 0.015 MeV and varied between 14.55 and 16.09. The Zeff decreases when we replaced the CaO by Al2O3. The half value layer was reported and we discussed the impact of the density of the glasses on the HVL values. In the low energy range, the HVL values are small and the different compositions have close HVL. For E>0.08 MeV, the HVL is higher than 1 cm for all glasses, while for E> 0.2 MeV, the HVL becomes higher than 2 cm for all glasses. The glass with composition of 35CaO-5Al2O3-60SiO2 has better attenuation performance than the other glasses in this study.

Nanoconfined Synthesis of Lead Sulfide Quantum Dots Embedded in Mesoporous Aluminosilicate Glass with Adjustable Near-Infrared Broadband Luminescence

Nanoconfined Synthesis of Lead Sulfide Quantum Dots Embedded in Mesoporous Aluminosilicate Glass with Adjustable Near-Infrared Broadband Luminescence

Theoretical Insights into the 27Al NMR Parameters of Binary Aluminosilicate Glass and Their Relationship to the Atomic and Electronic Structure

Theoretical Insights into the ²⁷Al NMR Parameters of Binary Aluminosilicate Glass and Their Relationship to the Atomic and Electronic Structure

The first demonstration of wavelength-tunable Yb3+-doped low silica calcium aluminosilicate (LSCAS) glass lasers

We report on the first demonstration of diode-pumped wavelength-tunable Yb3+-doped low silica calcium aluminosilicate (LSCAS) glass lasers. Using a 976 nm diode laser as pump source, a Yb:LSCAS laser has been successfully achieved with a maximum output power of about 0.28 W. Using an MgF2 thin plate as birefringence filter, we have found that the lasing wavelength can be tuned with a range of about 60 nm. We have also analyzed the intracavity round-trip loss of the current laser cavity, and related it to the optical quality of the used Yb glass. This sheds light on the path of the development of upcoming Yb3+ glass lasers in the future since it has many advantages, and after improving the optical quality, the wide and smooth emission spectrum of Yb:LSCAS will be very conducive to obtaining femtosecond pulse lasers.

Composition formulas of silicate glasses

AbstractWe here extend the cluster‐plus‐glue‐atom model, originally developed for metallic glasses, to the interpretation of silicate glass compositions. By referring to β‐SiO2 crystal structure and to the widely recognized random network model, our model identifies a 16‐basic‐unit (or 32‐cation) composition formula {M1+2O}n–{M3+2O3}16−(m+n)–{M4+2O4}m, where monovalent unit {M1+2O} and quadrivalent unit {M4+2O4} cannot coexist and the trivalent units {M3+2O3} are constructed from pure trivalent cations such as {(Al,B)2O3} and from combinations of monovalent and divalent cations with the base quadrivalent Si such as {(Na,K)2/3Si4/3O3} and {(Mg,Ca)SiO3}. After analyzing some glasses of historical importance, it is pointed out that most of soda–lime–silica and aluminosilicate glasses satisfy closely {M3+2O3}16, as exemplified by ancient glasses as well as by modern ones, such as Container glass, 1980, Jena Standard Glass, and Corning Gorilla glasses of the first generation. On the other hand, borosilicate glasses feature extra {Si2O4} units ranging from 4 to 9.5 in their 16‐unit formulas, as exemplified by Corning E‐glass and Schott thermometer glass with {Si2O4}4 and Corning Pyrex with {Si2O4}9.5 containing the highest silica proportion. The number of monovalent cations in 32‐cation formulas follows linear dependences on the average cation valence e/c and on the 16‐unit parameters 2 m − 4n, showing that, except alkali‐free glasses, the compositions of soda–silicate glasses converge to 2N2 + N3 ≈ 8, where N2 and N3 are, respectively, the numbers of divalent and trivalent cations in the 32‐cation formula. The revelation of the composition rule shows the capacity of the cluster‐plus‐glue‐atom model in understanding the compositions of complex glassy systems.

Magnetic boson peak in classical spin glasses

We revisited spin dynamics in archetypical classical spin-glass (SG) systems, such as Cu1−xMnx (x=0.017, 0.034, and 0.067) dilute alloys and iron aluminosilicate glass, using a modern neutron scattering spectrometer with high neutron flux. The former is crystalline, and the latter is amorphous, where their SG state is well separated from magnetically ordered phases. Bose-scaled localized magnetic excitations were observed in both compounds below the spin-freezing temperature (Tf). The spectrum exhibits a maximum at low energy and a broad tail on the high-energy side. The excitation energy tends to be higher for the material with higher Tf. Above Tf, the spectrum considerably changes with temperature, thereby indicating the emergence of the magnetic relaxation process. The magnetic excitation in the SG state has much in common with the boson peak in structural glasses. We consider that the Bose-scaled broad excitation peak is an elementary excitation inherent in disordered systems. Published by the American Physical Society 2024

Impacts of substituting magnesium with zinc on crystallization behaviors in an aluminosilicate glass.

A series of zinc-magnesium mixed aluminosilicate glasses with the molar composition (1-r)MgO·rZnO·Al2O3·2.5SiO2, where r = 0.00, 0.25, 0.50, 0.65, 0.75, and 1.00, were fabricated to probe the effects of substitution of magnesium with zinc on crystallization behaviors. Based on the evolution of phase compositions as revealed by calorimetric behaviors and X-ray diffraction patterns, a series of transparent surface crystallized glasses ranging from high transparency for the pure Zn-end member to heavy translucency for the pure Mg-end member were fabricated through heat treatment at the first crystallization peak temperature for 20 min. With the substitution of Mg with Zn, the evolution of morphology unveiled by optical microscopy is ascribed to the alteration of crystal phases formed from the sole metastable Zn-β quartz solid solution to the coexistence of polycrystal phases containing Zn-β quartz solid solution, μ-cordierite, or α-cordierite. These findings are very helpful for optimizing the performance of crystallized aluminosilicate glasses.

Densification of sodium and magnesium aluminosilicate glasses at ambient temperature: structural investigations by solid-state nuclear magnetic resonance and molecular dynamics simulations.

Sodium and magnesium aluminosilicate glasses with compositions 20Na2O-20Al2O3-60SiO2 (NAS) and 20MgO-20Al2O3-60SiO2 (MAS) were subjected to a 12 and 25 GPa compression and decompression at room temperature, resulting in density increases from 3.7% to 5.3% (NAS) and from 8.2 to 8.4% (MAS), respectively. The pressurization at 25 GPa was done on 17O-enriched glasses, to facilitate characterization by 17O NMR. The structural changes associated with this process have been investigated by solid state 29Si, 27Al, 23Na, 25Mg, and 17O magic-angle spinning NMR and compared with the situation in thermally relaxed glasses and/or glasses prepared at ambient pressure. While in the Na aluminosilicate glass only subtle structural changes were observed in a sample densified at 12 GPa, the average coordination number of Al 〈CN(Al)〉 increases moderately from 4.00 to 4.26 by pressurization at 25 GPa. In the Mg-based system, 〈CN(Al)〉 increases from 4.34 to 4.57 to 4.83 in the sequence 10-4 GPa → 12 GPa → 25 GPa. The experimental result at 25 GPa was qualitatively confirmed by molecular dynamics (MD) simulations. Overall, pressurization results in more positive 29Si and 17O chemical shifts, most likely reflecting a reduction in the Si-O-Si and Si-O-Al bonding angles in the pressurized glasses. Furthermore, the results are also consistent with either an increased number of non-bridging O-atoms upon pressurization, or a larger number of Si-O-Al or Al-O-Al linkages. The significantly higher sensitivity of MAS, compared to NAS glass, to an increase in 〈CN(Al)〉 upon pressurization, provides a good structural rationale for its significantly higher crack initiation resistance.

Dispersion, ionic bonding and vibrational shifts in phospho-aluminosilicate glasses.

Understanding the relationships between structure and properties of aluminosilicate glasses is of interest in magmatic studies as well as for glass applications as mechanical or optical components. Glass properties may be tailored by the incorporation of additional elements, and here we studied the effect of phosphate incorporation on refractive index and the degree of ionic bonding in aluminosilicate glasses. The studied glasses in the system SiO2-Al2O3-Na2O-P2O5 had a metaluminous composition (Al:Na = 1) with the content of SiO2 ranging from 50 to 70 mol% and of P2O5 from 0 to 7.5 mol%. Refractive index was measured at four wavelengths from visible to near-infrared and found to decrease both with increasing P2O5 content (at the expense of NaAlO2) and with increasing SiO2 content (by substitution of SiO4 for AlO4 groups). This trend correlated with a decrease in density while, additionally, the formation of Al-O-P bonds with an SiO2-like structure may account for this change. The degree of ionic bonding, assessed via optical basicity and oxygen polarisability, decreased with increasing P2O5 and SiO2 content. Despite the complexity of the studied glasses, oxygen polarisability and optical basicity were found to follow Duffy's empirical equation for simple oxide glasses. In the high frequency infrared and Raman spectra, band shifts were observed with increasing P2O5 and SiO2 content. They indicated changing average bond strength of the glass network and showed a linear correlation with optical basicity.

Revealing the evolution of local structures in the formation process of alkaline earth metal cation-containing zeolites from glasses.

Alkaline earth metal cations are ubiquitously present in natural zeolites but less exploited in synthetic zeolites due to their low solubility in water, and hence it remains elusive how they contribute to zeolite formation. Herein, harmotome, a PHI-type zeolite with Ba2+, is readily synthesized from a Ba-containing aluminosilicate glass. This glass-to-zeolite transformation process, in particular the structure-regulating role of Ba2+, is investigated by anomalous X-ray scattering and high-energy X-ray total scattering techniques. The results demonstrate that the steady Ba2+-aluminosilicate interactions not only help prevent the precipitation of barium species under alkaline synthetic conditions, but also dictate the local structures with distinct interatomic distances between the Ba2+ and the surrounding aluminosilicate species throughout the transformation process, which lead to the successful formation of harmotome without detectable impurities. This study highlights the usefulness of the comprehensive X-ray scattering techniques in revealing the formation scheme of the zeolites containing specific metal species. In addition, a promising alternative approach to design and synthesize zeolites with unique compositions and topologies by using well-crafted glasses with suitable metal cation dopants is demonstrated.

Yb2+-Doped Silicate Glasses as Optical Sensor Materials for Cryogenic Thermometry.

Optical sensors constitute attractive alternatives to resistive probes for the sensing and monitoring of temperature (T). In this work, we investigated, in the range from 2 to 300 K, the thermal behavior of Yb2+ ion photoluminescence (PL) in glass hosts for cryogenic thermometry. To that end, two kinds of Yb2+-doped preforms, with aluminosilicate and aluminophosphosilicate core glasses, were made using the modified chemical vapor deposition (MCVD) technique. The obtained preforms were then elongated, at about 2000 °C, to canes with an Yb2+-doped core of about 500 µm. Under UV excitation and independently of the core composition, all samples of preforms and their corresponding canes presented a wide visible emission band attributed to Yb2+ ions. Furthermore, PL kinetics measurements, recorded at two emission wavelengths (502 and 582 nm) under 355 nm pulsed excitation, showed an increase, at very low T, followed by a decrease in lifetime until room temperature (RT). A modified two-level model was proposed to interpret such a decay time dependence versus T. Based on the fit of lifetime data with this model, the absolute (Sa) and relative (Sr) sensitivities were determined for each sample. For both the preform and its corresponding cane, the aluminophosphosilicate glass composition featured the highest performances in the cryogenic domain, with values exceeding 28.3 µsK-1 and 94.4% K-1 at 30 K for Sa and Sr, respectively. The aluminophosphosilicate preform also exhibited the wider T operating range of 10-300 K. Our results show that Yb2+-doped silicate glasses are promising sensing materials for optical thermometry applications in the cryogenic domain.

Regulating the valence state of lead ions in lead aluminosilicate glass to improve the passivation performance for advanced chip packaging

Eliminating surface ion contamination, increasing the reverse breakdown voltage and reducing the leakage current are extremely important for semiconductor devices. Herein, we demonstrated that regulating the valence state of lead ions in lead aluminosilicate glass can efficiently improve the performance of glass passivation technique for chip packaging. It was found that heat treatment technique can be utilized to control valence state of lead ions from +4 into +2 in 20PbO-4.8Al2O3-75.2SiO2 (mol%) (PAS) glass powder, which induces transformation of [PbO3] units into stable glass former units of [PbO4] and generates a free state and charge compensator of Pb2+, therefore contributing to a more stable structure and discoloration of glass. As a result, the optical band gap of glass powder was enhanced from 4.1772 to 4.3184, which could significantly improve glass insulation. As a demonstration of chip packaging, PAS glass powder, after heat treatment processing into a paste for the passivation layer of metal–oxide–semiconductor (MOS) structure devices shows a tight and integrated structure and exhibits a lower fixed charge density from 3.97 × 1010cm−2 to 2.73 × 1010 cm−2. This work provides techniques to adjust the structure of glass to enhance the passivation performance of glass for chip packaging.

High pressure-driven effects on the structural and spectroscopic attributes of Eu3+-doped amorphous silicates

The present study focuses on synthesizing and investigating the structure of Eu3+-doped sodium calcium silicate and calcium alumino silicate glasses under extreme high-pressure conditions. For a thorough understanding of glassy systems in extreme conditions, we conducted in-situ micro-luminescence experiments using a diamond anvil cell, reaching pressures up to 16 GPa. Hydrostatic pressure demonstrated a notable impact on luminescence, attributed to the nephelauxetic effect causing the contraction of central-ion-ligand distances. The band transitions of Eu3+ from the 5D0 to 7F1,2 states revealed pronounced pressure-induced splitting, highlighting the pressure influence on crystal-field properties. The energy shifts for the 5D0 → 7F1 transitions were determined to be 0.14 nmGPa−1 and 0.20 nmGPa−1 for sodium calcium silicate and calcium alumino silicate, respectively. These distinct slope differences indicated a lower structural adaptability of the former glass, resulting in reduced deformability under high-pressure conditions. Furthermore, as pressure increased, the asymmetry ratio of the 5D0 → 7F2/1 transitions decreased, though it consistently maintains levels higher than unity, reflecting the highly asymmetric environment surrounding Eu3+ ions. The estimated elastic limit for both samples was approximately 7 GPa. To assess pressure-induced changes in the local environment, Judd-Ofelt intensity parameters were employed for the calcium alumino silicate glass. The trends observed throughout compression revealed that Ω2 > Ω4 up to 6.8 GPa, while Ω2 < Ω4 for higher pressures, indicating higher covalency between Eu3+ ions and ligands in the elastic domain compared to the plastic domain. The observed increase in Si and Al coordination in the plastic domain was found to play a role in these parameters.

Characterizing the flexural/damage behavior of Aluminosilicate glass at low/high loading rates: Application of SHPB for mode-1 loading of laminated glass

Understanding the flexural response of monolithic and laminated glass is essential for making informed choices while selecting glass for varying applications. That is because the behavior of monolithic and laminated glass may not necessarily be the same under certain loading conditions and assessing their performance differences helps in determining their suitability for specific applications. The presented work is aimed at quantifying the flexural/damage behavior of monolithic and laminated glass. Quasi-static and dynamic flexural tests were conducted on monolithic and laminated glass in mode-1 loading while maintaining identical loading and support interfaces. In the first phase, quasi-static flexural tests were performed, and results were quantitatively compared by two approaches: Effective Thickness Approximation (ETA) and the theory of Thick Sandwiched Beams (TSB). Experimentally observed deflection corroborated with both the analytical methods; the absolute error remained less than 2.5% and 0.5% for ETA and TSB, respectively. Importantly, failure of the laminate was witnessed at approximately 50% lower force compared to its monolithic counterpart, which was attributed to the span length of the specimen and the interlayer’s shear stiffness. Fractography was performed to elicit Aluminosilicate glass’s mirror constant and fracture surface energy, as 1.86 MN/m3/2 and 3.95 J/m2, respectively. In Phase-2, Dynamic flexural tests were conducted on a novel Electromagnetic Split Hopkinson Pressure Bar (ESHPB), and an experimental-numerical coupled approach was introduced to analyze the results. The results established that the adverse effects of shorter span length on the flexural strength of laminated glass are mitigated, primarily due to the viscoelastic response of the interlayer. The reprographic images attributed the fracture of monolithic and laminated glass specimens solely to the bending-induced stresses.

Effect of redox conditions of glass melting on the structure and the properties of titanium-containing gahnite glass-ceramics

In order to develop glass-ceramics containing ions of variable valence in lower oxidation states, it is important to know how changing the redox conditions of glass melting affects structure and properties of glass-ceramics. The zinc aluminosilicate glass nucleated by TiO2 was melted with and without addition of As2O3 and heat-treated from 720° to 1350°C to obtain gahnite-based glass-ceramics. DSC, XRD analysis, Raman spectroscopy and TEM studies revealed that variation of glass melting redox conditions affects kinetics of liquid phase separation and rutile crystallization, composition and structure of gahnite and rutile, crystallization of the residual glass, and does not affect kinetics of gahnite crystallization, gahnite and rutile fractions and structure of glass-ceramics. In glass-ceramics prepared from glasses melted without As2O3, absorption in the visible and near-IR spectral ranges is due to octahedrally coordinated Ti3+ ions in gahnite nanocrystals. The study is important for development of rare-earth-free phosphors.

Effect of alkali and alkaline-earth metal oxides on the chemical strengthening properties of sodium alumino-silicate glasses

Silicate based alumino-sodium (SAS) glasses were fabricated with various alkali (Li2O and K2O) and alkaline-earth metal (MgO and CaO) oxides to study their influence on chemical strengthening characteristics such as surface compression stress (CS) and depth of layer (DOL) after ion exchange of Na+ with K+. Introducing Li2O instead of Na2O decreased DOL while increasing CS up to 5.0 mol. % of Li2O. In contrast, replacing Na2O content with K2O increased DOL while decreasing CS. When alkaline-earth oxides such as MgO and CaO were substituted for Na2O, both CS and DOL decreased. Micro-Raman spectroscopy was used to study structural changes induced by alkali and alkaline-earth oxides and their impact on ion exchange properties. The inter-diffusion coefficients of K+ ions were predicted by employing the Boltzmann-Matano equation to support the chemical strengthening effect of various alkali and alkaline-earth elements in SAS glasses.

Structure, mechanical, and chemical performance evolution of aluminosilicate glass modified by Nd2O3

Structure, mechanical, and chemical performance evolution of aluminosilicate glass modified by Nd2O3

Природа сфероидального золота Среднекыввожской россыпи на Среднем Тимане

A comprehensive mineralogical study of 13 samples of spheroidal gold from schlich concentrates of the Middle Kyvvozh gold placer, which is part of the Kyvvozh gold placer field located in the central part of the Volsk-Vym ridge of the Middle Timan, was carried out. The presence of both natural and technogenic gold in concentrates was established. Natural placer spheroidal gold is characterized by a worn surface with oxide films and the development of a high-grade corrosion rim. Technogenic gold spheroids have a polygonal-mosaic tuberculate-pitted or smooth surface, the presence of aluminosilicate glasses and slags in the form of crusts or inclusions in the matrix, the presence of mineral inclusions and impurities of platinum group metals, tin and lead, which are not characteristic of native gold. Natural spheroids were formed by natural smoothing in the water flow during the formation of the placer. The formation of technogenic spheroids is associated with the impact of high-temperature plasma on the concentrate enriched in placer gold and platinoids, which occurs during electric welding undertaken during the repair work of the flushing devices. The results of the study should help to avoid errors in the interpretation of the genesis of such gold and, as a result, in determining the nature of the primary sources of placers.