Related papers: The vibrational dynamics of vitreous silica: Class…
Ultra-stable glasses prepared from the physical vapor deposition of organic molecules present a very low density of two-level states, the kind of glass defects that determine their peculiar low temperature thermal properties. Numerical…
This Comment corrects two separate errors which previously appeared in the calculation of vibrational mode frequencies of tin spheres embedded in a silica matrix. The first error has to do with the vibrational frequency of a free elastic…
Inelastic X-ray Scattering measurements of the dynamics structure factor have bene performed on vitreous Beryllium Fluoride ({\it v-}BeF$_2$) at $T$=297 K in the momentum transfer, $Q$, range $Q$=1.5$\div$10 nm$^{-1}$. We find evidence of…
We summarize the salient features of our theory of non-phononic vibrational excitations in glasses [W. Schirmacher et al., Nature Comm. 15, 3107 (2024)]. Next, we provide further evidence of the non-universality of the $\omega^4$ scaling of…
The relaxation dynamics and the vibrational spectra of amorphous solids, such as metal alloys, have been intensely investigated as well separated topics in the past. The aim of this review is to summarize recent results in both these areas…
New temperature dependent inelastic x-ray (IXS) and Raman (RS) scattering data are compared to each other and with existing inelastic neutron scattering data in vitreous silica (v-SiO_2), in the 300 - 1775 K region. The IXS data show…
In glasses, atomic disorder combined with atomic connectivity makes understanding of the nature of the vibrations much more complex than in crystals or molecules. With a simple model, however, it is possible to show how disorder generates…
This study presents a comprehensive computational investigation of the vibration density of states (VDOS) of a silica nanopore, systematically evaluating a range of force fields against inelastic neutron scattering results. We analyze the…
In the present work we have performed an ab initio calculation of vibrational properties of CuTe2O5 by means of density functional theory method. One has compared calculated values with known experimental data on Raman and infrared…
The interrelation of dynamic processes active on separated time-scales in glasses and viscous liquids is investigated using a model displaying two time-scale bifurcations both between fast and secondary relaxation and between secondary and…
The dynamics of a soft sphere model glass, studied by molecular dynamics, is investigated. The vibrational density of states divided by $\omega^2$ shows a pronounced boson peak. Its shape is in agreement with the universal form derived for…
We present the results of a molecular dynamics computer simulation in which we investigate the dynamics of silica. By considering different system sizes, we show that in simulations of the dynamics of this strong glass former surprisingly…
We have studied the normal modes of hydrogenated and oxidized silicon nanocrystals, namely SiH4 (silan), H2SiO (silanon), Si10H16 and Si10H14O. The small clusters (SiH4 and H2SiO) have been used for convergence tests and their bondlengths…
We discuss a novel approach that allows to obtain effective potentials from ab initio trajectories. Our method consists in fitting the weighted radial distribution functions obtained from the ab initio data with the ones obtained from…
A structural model of a one-component $\sigma$-phase crystal has been constructed by means of molecular dynamics simulation. The phonon dispersion curves and the vibrational density of states were computed for this model. The dependence of…
We investigate the vibrational properties of topologically disordered materials by analytically studying particles that harmonically oscillate around random positions. Exploiting classical field theory in the thermodynamic limit at $T=0$,…
Atomic vibrations in perfect, slightly defective or mixed crystals are to a large extent well understood since many decades. Theoretical descriptions are thus in excellent agreement with the experiments. As a consequence, phonon-related…
The structure and vibrational density of states (VDOS) of polymer glasses are investigated using numerical simulations based on the classical Kremer-Grest bead-spring model. We focus on the roles of chain length and bending stiffness, the…
We present a combined experimental and theoretical study of the surface vibrational modes of the topological insulator Bi$_2$Te$_3$. Using high-resolution helium-3 spin-echo spectroscopy we are able to resolve the acoustic phonon modes of…
We explore, by means of inelastic neutron scattering, the extent of changes in dynamic correlations induced by thermal poling of vitreous $SiO_2$. The measured vibrational density of states shows an excess of modes in certain frequency…