Journal of Non-Crystalline Solids: X最新文献

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.

The mechanism of non-congruent growth of a crystal from glass has been sought using molecular dynamics simulations. Specifically, as a model of this process, the growth of a lithium niobate (LiNbO₃) crystal seed sandwiched between two lithium niobosilicate (LNS) glass slabs has been simulated as a function of time and temperature. The growth of pre-existing crystal is strongly affected by the orientation of crystal seed, temperature, and the SiO₂ concentration in the surrounding LNS glass matrix. The orientation of LiNbO₃ seed surface that has inherently larger interplanar distance results in a relatively slower crystal growth. The addition of SiO₂ to LNS system significantly decreases the crystal growth, which primarily occurs in the region devoid of Si. The suppressive effect of SiO₂ on growth rate can be traced to the existence of defect complex comprising of Si substituted at the Nb site and a nearby Nb vacancy.

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.

Glass transition temperature and related dynamics play an essential role in amorphous materials research since many of their properties and functionalities depend on molecular mobility. However, the temperature dependence of the structural relaxation time for a given glass former is only experimentally accessible after synthesizing it, implying a time-consuming and costly process. In this work, we propose combining artificial neural networks and disordered systems theory to estimate the glass transition temperature and the temperature dependence of the main relaxation time based on the knowledge of the molecule's chemical structure. This approach provides a way to assess the dynamics of molecular glass formers, with reasonable accuracy, even before synthesizing them. We expect this methodology to boost industrial development, save time and resources, and accelerate the scientific understanding of structure-properties relationships.