Article
Chemistry, Physical
Edan Lerner, Eran Bouchbinder
Summary: Glassy solids exhibit a wide variety of thermomechanical properties, which are believed to be related to nonphononic, low-energy quasilocalized excitations (QLEs). Recent computer simulations have revealed the emergence of QLEs during vitrification upon cooling from a melt. Progress has been made in understanding the emergence of QLEs in structural glasses over the past three decades, but challenges still exist.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Ahmed El Hamdaoui, El Mehdi Ghardi, Achraf Atila, Hicham Jabraoui, Michael Badawi, Abdellatif Hasnaoui, Said Ouaskit
Summary: In this study, molecular dynamics simulations were used to investigate binary and ternary silicate glasses with different network intermediates and modifier oxides. The vibrational density of states and boson peak were analyzed for all glasses, and their correlation with elastic constants, structural properties, and dynamical properties were discussed. The classification of alkali oxides as modifiers was questioned, and it was suggested that Li2O acts as a pseudo-intermediate oxide in lithium silicate glasses. This claim was supported by the effect of Li on various vibrational modes. The study also found a correlation between boson peak intensities and the Voronoi volume of specific species and vibrational mean square displacements.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
V. N. Novikov
Summary: Research shows that normalized rms fluctuation of shear modulus in glasses correlates with fragility, with higher fragility leading to smaller fluctuations on a medium range scale, while on a smaller scale, fluctuations are much smaller in amplitude and may either increase or decrease with increasing fragility. Extrapolation predicts the disappearance of the boson peak at an upper limit to fragility asymptotic to 180.
Article
Spectroscopy
M. A. Shevchenko, L. L. Chaikov, N. Tcherniega
Summary: This Letter reports the experimental effective coherent multiple Stokes and anti-Stokes high-order components generation by Stokes pulse injection at the process of stimulated low-frequency Raman scattering, which can be used for generating the tunable spectral comb consisting of several equidistant spectral lines separated by a constant frequency spacing of several GHz.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2021)
Article
Chemistry, Physical
Lijin Wang, Grzegorz Szamel, Elijah Flenner
Summary: The density of states for two-dimensional glasses exhibits different system-size scaling depending on the number of particles. For systems with fewer than 100 particles, the density of states scales with the system size as if all the modes were plane-wave-like. However, for systems with more than 100 particles, the cumulative density of states below the first transverse sound mode frequency shows a different system-size dependence, suggesting quasi-localized modes. In addition, the cumulative density of states scales with the frequency as a power law with an exponent that leads to β = 3.5 for the density of states.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Andreij C. Gadelha, Douglas A. A. Ohlberg, Cassiano Rabelo, Eliel G. S. Neto, Thiago L. Vasconcelos, Joao L. Campos, Jessica S. Lemos, Vinicius Ornelas, Daniel Miranda, Rafael Nadas, Fabiano C. Santana, Kenji Watanabe, Takashi Taniguchi, Benoit van Troeye, Michael Lamparski, Vincent Meunier, Viet-Hung Nguyen, Dawid Paszko, Jean-Christophe Charlier, Leonardo C. Campos, Luiz G. Cancado, Gilberto Medeiros-Ribeiro, Ado Jorio
Summary: The twisted bilayer graphene undergoes self-organized lattice reconstruction, resulting in the formation of a superlattice that modulates vibrational and electronic structures, leading to phenomena such as strong correlations and superconductivity. Although experimental techniques and theoretical models face challenges in observing and describing these effects, nano-Raman spectroscopy can localize some vibrational modes and provide insights into the effects of electron-phonon coupling on the material properties.
Article
Multidisciplinary Sciences
Mario Gonzalez-Jimenez, Trent Barnard, Ben A. Russell, Nikita V. Tukachev, Uros Javornik, Laure-Anne Hayes, Andrew J. Farrell, Sarah Guinane, Hans M. Senn, Andrew J. Smith, Martin Wilding, Gregor Mali, Motohiro Nakano, Yuji Miyazaki, Paul McMillan, Gabriele C. Sosso, Klaas Wynne
Summary: It has been discovered that the boson peak in glasses, which is an excess in heat capacity or an additional peak in the terahertz vibrational spectrum, can be isolated in liquids of highly symmetric molecules using depolarized Raman scattering. This peak is linked to the formation of clusters consisting of about 20 molecules. These findings represent a significant step toward understanding the physics of vitrification.
NATURE COMMUNICATIONS
(2023)
Review
Spectroscopy
Md Shafiul Azam, Dennis Hore
Summary: This perspective discusses the use of Raman spectroscopy to interpret surface-selective vibrational spectra in bulk aqueous phases. By overcoming the limitations of spectral fitting, it provides an experimental route for analyzing spectral features, even in cases with only a single set of beam polarizations. Two-dimensional correlation analysis is used as a general method, with a specific application to vibrational spectra. The combination of sum-frequency and Raman data allows for unraveling characteristic features of aqueous interfaces, such as the surface preference of adsorbed species relative to their bulk concentration.
JOURNAL OF RAMAN SPECTROSCOPY
(2022)
Article
Materials Science, Ceramics
Chengjun Liu, Rui Zhang, Xuan Zhao, Jixiang Jia, Yi Min
Summary: The structures of phosphorus in CaO-SiO2-P2O5 glasses were analyzed through Raman spectroscopy and calibrated using P-31 MAS-NMR spectroscopy. It was found that CaO had a stronger ability to depolymerize [PO4]-tetrahedrons compared to [SiO4]-tetrahedrons, and the addition of P2O5 increased the degree of polymerization of Si.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Chemistry, Physical
Grzegorz Szamel, Elijah Flenner
Summary: In this study, we analyze sound attenuation starting directly from the microscopic equations of motion and derive an exact expression for the zero-temperature sound damping coefficient. We verify that the sound damping coefficients calculated from our expression agree very well with results from independent simulations of sound attenuation. Small wavevector analysis shows that sound attenuation is primarily determined by the non-affine displacements' contribution to the sound wave propagation coefficient coming from the frequency shell of the sound wave.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Subodh S. Khire, Nityananda Sahu, Shridhar R. Gadre
Summary: This article introduces a software package MTASpec, based on the Fragmentation-based molecular tailoring approach, for computing vibrational spectra of large molecular systems. The accuracy and efficiency of MTASpec have been assessed, showing promising results for spectral studies of molecular systems on a computational economy.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Johanna Kolbel, Walter Schirmacher, Evgenyi Shalaev, J. Axel Zeitler
Summary: The model glass former glycerol and its aqueous mixtures were investigated with terahertz-time-domain spectroscopy. The results showed that the infrared absorption coefficient measured with THz-TDS can be related to the reduced Raman intensity and the reduced density of states. The study also found that the dynamics, boson peak, and vibrational dynamics were affected by the presence of clustered and unclustered water.
Article
Materials Science, Ceramics
Nektarios K. Nasikas, Angelos G. Kalampounias
Summary: By utilizing a nonconventional melting technique, researchers synthesized a series of calcium aluminate glasses and investigated the relationship between the low-frequency spectral changes and elastic properties. The study revealed a systematic dependence of the Boson Peak frequency on the CaO content, which is correlated with the elastic properties.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Physical
Rayan Zaiter, Marc Dussauze, Marcelo Nalin, Evelyne Fargin, Frederic Adamietz, Sylvain Danto, Olivier Toulemonde, Thierry Cardinal
Summary: A series of new transparent and magnetic barium gallogermanate glasses with different Gd2O3 contents were synthesized and characterized. The addition of Gd2O3 affected the glass structure and magnetic properties. These glasses have the potential to be used in optical fiber production.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Mathematics, Applied
Pradyumna Kumar Sahoo, S. Chatterjee
Summary: This paper investigates the vibrational resonance and control of a nonlinear tilted cantilever beam under combined multi-harmonic low and non-resonant, high-frequency excitation. The research explores the non-trivial effects of high-frequency excitation on parametric amplification, vibrational resonance, and chaos, which have not been previously reported. The results demonstrate that high-frequency excitation can effectively control parametric amplification by shifting the resonance curve and increasing the effective damping.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
