The origin of several emergent mechanical and dynamical properties of structural glasses is often attributed to populations of localized structural instabilities, coined quasilocalized modes (QLMs). Under a restricted set of circumstances, glassy QLMs can be revealed by analyzing computer glasses' vibrational spectra in the harmonic approximation. However, this analysis has limitations due to system-size effects and hybridization processes with low-energy phononic excitations (plane waves) that are omnipresent in elastic solids. Here we overcome these limitations by exploring the spectrum of a linear operator defined on the space of particle interactions (bonds) in a disordered material. We find that this bond-force-response operator offers a different interpretation of QLMs in glasses and cleanly recovers some of their important statistical and structural features. The analysis presented here reveals the dependence of the number density (per frequency) and spatial extent of QLMs on material preparation protocol (annealing). Finally, we discuss future research directions and possible extensions of this work.
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http://dx.doi.org/10.1103/PhysRevE.104.044905 | DOI Listing |
J Phys Chem C Nanomater Interfaces
January 2025
Institute of General, Inorganic and Theoretical Chemistry Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria.
Novel anode materials for lithium-ion batteries (LIBs) are constantly being explored to further improve battery performance. In this work, ReaxFF molecular dynamics (MD) simulations are performed to model the early stages in the synthesis of nanostructured silicon carbide (SiC), which is one such promising material. The focus lies on its precursor, silicon oxycarbide glass of composition (SiOC) (17 mol% Si, 28 mol% O, and 54 mol% C), in the following referred to as SiOC.
View Article and Find Full Text PDFChem Sci
October 2024
Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University Chongqing 400044 China
Metal halide perovskites (MHPs) have been developed rapidly for application in light-emitting diodes (LEDs), lasers, solar cells, photodetectors and other fields in recent years due to their excellent photoelectronic properties, and they have attracted the attention of many researchers. Perovskite LEDs (PeLEDs) show great promise for next-generation lighting and display technologies, and the external quantum efficiency (EQE) values of polycrystalline thin-film PeLEDs exceed 20%, which is undoubtedly a big breakthrough in lighting and display fields. However, the toxicity and instabilities of lead-based MHPs remain major obstacles limiting their further commercial applications.
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January 2025
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of Electrical and Electronic Engineering, North China Electric Power University, Beijing 102206, People's Republic of China.
Given extremely high porosity, aerogels have demonstrated remarkable advantages in serving as thermal insulation and wave-transparent materials. Unfortunately, their practical applications are greatly confined by their inherent fragility. The recent emergence of polymer aerogels presents an ideal platform for the development of flexible aerogel films.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Institute of Chemistry, Military University of Technology, Kaliskiego 2, PL-00908 Warsaw, Poland.
Molecular arrangement in the chiral smectic phases of the glassforming (S)-4'-(1-methylheptylcarbonyl)biphenyl-4-yl 4-[7-(2,2,3,3,4,4,4-heptafluorobutoxy) heptyl-1-oxy]benzoate is investigated by X-ray diffraction. An increased correlation length of the positional short-range order in the supercooled state agrees with the previous assumption of the hexatic smectic phase. However, the registered X-ray diffraction patterns are not typical for the hexatic phases.
View Article and Find Full Text PDFJ Dent Sci
December 2024
Faculty of Dentistry, The University of Hong Kong, Hong Kong, S.A.R., China.
The World Health Organization (WHO) has added glass ionomer cement (GIC) to the WHO Model List of Essential Medicines since 2021, which represents the most efficacious, safe and cost-effective medicines for priority conditions. With the potential increase in the use of GIC, this review aims to provide an overview of the clinical application of GIC with updated evidence in restorative and preventive dentistry. GIC is a versatile dental material that has a wide range of clinical applications, particularly in restorative and preventive dentistry.
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