Journal of Non-Crystalline Solids: X最新文献

Mixed modifier effect refers to the nonlinear variations of glass properties when mixing different types of modifier ions. The effect plays an important role since it can be applied to design glasses with controlled properties and it is also related to the raw materials selection. In this review, we will summarize the recent important progress on the mixed modifier effect in oxide glasses. The effect has been found in various properties, but we mainly focus on glass transition temperature (T_g), hardness (H), elastic modulus (E), and coefficient of thermal expansion (α) since these properties are critical in glass manufacture and products performance. Different properties exhibit unique features and many theories are proposed to account for the effect. The compositional dependence of these properties is reviewed and the theories proposed to explain this effect are discussed. Moreover, we suggest some future directions for the further work on the mixed modifier effect.

Low melting Li₂O-PbO-B₂O₃, Me₂O-ZnO-B₂O₃, Me = Li, Na, K, Rb and CaO-ZnO-B₂O₃ glasses were studied with Raman and infrared spectroscopies to advance the structural understanding of zinc borate glasses as potential candidates for substitution of lead containing glasses.

Although the effect of type of alkali ions on the number (N₄) of fourfold coordinated boron (B₄) in the glasses is small, the alkali ions direct the type of borate groups, i.e., pentaborate in lithium, sodium, and calcium zinc borate glasses, as well as diborate in potassium and rubidium containing ones. Both groups were simultaneously found in Li₂O-PbO-B₂O₃. Alkali ions are mainly responsible for the formation of B₄-units and metaborate. Zinc ions favorably compensate non-bridging oxygen and partially form ZnO₄.

With decreasing N₄ and field strength of the alkali ions the atomic packing density, glass transition temperature and Young's Modulus also decrease. The coefficient of thermal expansion increases with decreasing N₄.

Fracture and damage ascribed to the intrinsic brittleness of amorphous oxide glasses are crucial problems for the daily use of glass products. Because the latest developments in glass and glass-ceramics technologies have further broadened their applications, the safety issues become increasingly important. Computational modeling and simulation are now indispensable in the design and analysis of glass quality and safety. This review, therefore, provides an overview of the state-of-the-art fracture modeling/simulation techniques ranging from atomistic scale to continuum scale. In addition to the fundamental theories, typical and recent studies using a variety of continuum methods are introduced. This review also covers the application examples of classical molecular dynamics (CMD) simulations and reactive CMD simulations to investigate the fracture and damage evolutions in glass and glass-ceramics. Advanced multiscale modeling techniques that bridge atomistic and continuum method are also introduced for modeling amorphous materials.

The disordered structure of glass has been an attractive research topic. The heterogeneity of the disordered structures depends on probes that include theoretical, mathematical, and experimental approaches. This study presents structural ordering and defect formation observations for glass, glass-ceramics, and activator-doped glasses. The combination of these probes is expected to gain importance in the future given the broader range of perspectives (from microscopic (atomistic) to macroscopic) required to gain a deeper understanding of optically active glasses.

Although scientific journals stand as a reliable peer-reviewed source of data, it is often too tedious to manually extract relevant information from papers. This could be attributed to the unstructured data such as images, text, captions, and non-standard reporting of data in tables. Here, using natural language processing (NLP), we introduce a corpus of around ~100,000 glass science-related research papers and 106,238 images published in them, that allow for easy navigation and query-based searching through the database. We perform a meta-analysis of the literature in the corpus employing NLP tools. Specifically, we analyze the trends in the number of publications based on countries, research areas, and journals, thereby giving a broad overview of the progress in glass science over the last six decades. Further, as a demonstration of information extraction, we extract the structure factor data of ~450 glass compositions, thereby creating the first-ever public repository on the structure factor of glasses.

Developing novel scintillating glass with high density and intense radioluminescence is of critical importance for various radiation-related technologies. In this paper, Tb-doped Gd₂O₃-WO₃-SiO₂ (GWS) scintillating glass was prepared and investigated. The optical and scintillation properties are explored. And the optimal concentration of Tb activators in glass excited by UV-light and X-ray is determined. Moreover, annealing glass enables a unique glass bleaching phenomenon. Benefitting from the increasement in transparency, a notable improvement in photoluminescence (~195% enhancement in intensity) and radioluminescence (~146% enhancement in intensity) could be realized. The optical and structural characterizations reveal a dramatic change of W chemical valance state from W⁵⁺ to W⁶⁺, which is supposed to govern the decoloring process. Our research indicates that Tb-doped GWS scintillating glass can be a potential candidate for X-ray monitoring.

Phase change materials (PCMs) that store and release thermal energy via a reversible phase transition in the intermediate temperature range are a promising solution for renewable energy storage as they can be durable and inexpensive. Towards the development and understanding of new intermediate PCMs, this work describes a family of pyridinium ionic liquids and their thermophysical properties that show the potential of protic ionic liquids in the PCM field. Various pyridine structural isomers were used to explore the molecular patterns that affect the enthalpy of fusion and melting. The results show that small structural variations in the cation can change the thermophysical properties drastically; for example, melting temperatures varied between 357 ± 1 K and 499 ± 1 K, and enthalpies of fusion covered a wide spectrum from 38 to 190 J g⁻¹ ± 5%. The most promising results in terms of PCM application, and one of the best among all protic ionic liquids reported thus far, were obtained for 2-hydroxypyridinium methanesulfonate [2-OHpyH][CH₃SO₃] (T_m = 433 K and ΔH_f = 190 J g⁻¹).

The continuous development and improvement of interatomic potential models for oxide glasses have made classical molecular dynamics a powerful computational technique routinely used for studying the structure and properties of such materials on a par with the more advanced experimental techniques.

In this brief review, we retrace the development of the most used interatomic potential models from the earliest MD simulations up to now with a look at the possible future developments in this field due to the advent of the machine learning era and data-driven methods.

Thermoelectric materials capable of direct conversion between electricity and heat provide a broad prospect for power generation and refrigeration. As a family of potential thermoelectric materials, semiconducting chalcogenide glasses exhibit unique characteristics of easy to draw fiber, high Seebeck coefficient, low thermal conductivity and tunable electrical conductivity, endowing them with promising applications in wearable electronics. In this review, we summarize the recent advance on semiconducting chalcogenide glass for thermoelectric application. The design and fabrication method of semiconducting chalcogenide glasses are presented. The strategies for improving the thermoelectric performance of chalcogenide glasses are reported. Besides, the extensive applications of chalcogenide fibers in the fields of thermal sensing and positioning are overviewed. In the end, the challenges and perspectives for the future development of semiconducting chalcogenide glasses and fibers are discussed.

Glasses in the systems Me₂O-ZnO-B₂O₃ with Me = Li, Na, K, Rb (MeZB), Na₂O-ZnO-CuO-B₂O₃ (NZCuB), CaO-ZnO-B₂O₃ (CaZB), and Li₂O-PbO-B₂O₃ (LPbB) as a reference, were studied by differential thermal analysis, dilatometry, rotational viscometry, and heating microscopy. A decrease of viscosity and sintering range was found with decreasing number of fourfold coordinated boron. The viscosity of the alkali zinc borate glasses varies only slightly. LPbB and CaZB stand out by their reduced and increased viscosities, respectively. Sodium, potassium, and calcium zinc borate glasses possess a fragility above 76. All glasses were sintered to full density before crystallization. Mostly binary zinc borate phases govern crystallization. A ternary crystalline phase was detected only in the potassium containing sample. The Weinberg glass stability parameter ranges between 0.07 and 0.12. This is caused by the presence of several crystalline phases and varying melting points of even the same crystalline phase in different glass matrices.