Elastic Moduli of Permanently Densified Silica Glasses

Deschamps, Thierry; Margueritat, Jérémie; Martinet, C.; Mermet, A.; Champagnon, B.

doi:10.1038/srep07193

Cited by 87 publications

(91 citation statements)

References 62 publications

(113 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Strikingly, a clear crossover from generalized-Rayleigh to Rayleigh scaling at k on ≈ 2nm −1 is observed, strongly supporting the physical picture discussed in this paper. We note that according to a recent study [45], densification of vitreous silica at 8GPa does not lead to significant changes in the elastic moduli. Consequently, the differences observed in attenuation rates between vitreous and densified silica could not be attributed to shifts in characteristic phononic frequencies; rather, we propose that they emerge from the suppression of soft nonphononic quasilocalized modes.…”

Section: Experimental Evidencesupporting

confidence: 71%

Wave attenuation in glasses: Rayleigh and generalized-Rayleigh scattering scaling

Moriel

Kapteijns

Rainone

et al. 2019

The Journal of Chemical Physics

View full text Add to dashboard Cite

The attenuation of long-wavelength phonons (waves) by glassy disorder plays a central role in various glass anomalies, yet it is neither fully characterized, nor fully understood. Of particular importance is the scaling of the attenuation rate Γ(k) with small wavenumbers k → 0 in the thermodynamic limit of macroscopic glasses. Here we use a combination of theory and extensive computer simulations to show that the macroscopic low-frequency behavior emerges at intermediate frequencies in finite-size glasses, above a recently identified crossover wavenumber k † , where phonons are no longer quantized into bands. For k < k † , finite-size effects dominate Γ(k), which is quantitatively described by a theory of disordered phonon bands. For k > k † , we find that Γ(k) is affected by the number of quasilocalized nonphononic excitations, a generic signature of glasses that feature a universal density of states. In particular, we show that in a frequency range in which this number is small, Γ(k) follows a Rayleigh scattering scaling ∼ kd +1 (d is the spatial dimension), and that in a frequency range in which this number is sufficiently large, the recently observed generalized-Rayleigh scaling of the form ∼ kd +1 log(k0/k) emerges (k0 > k † is a characteristic wavenumber). Our results suggest that macroscopic glasses -and, in particular, glasses generated by conventional laboratory quenches that are known to strongly suppress quasilocalized nonphononic excitations -exhibit Rayleigh scaling at the lowest wavenumbers k and a crossover to generalized-Rayleigh scaling at higher k. Some supporting experimental evidence from recent literature is presented.

show abstract

Section: Experimental Evidencesupporting

confidence: 71%

Wave attenuation in glasses: Rayleigh and generalized-Rayleigh scattering scaling

Moriel

Kapteijns

Rainone

et al. 2019

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…This can be a direct consequence of performing simulations with adjusted densities to the experimental ones during the cooling schedule, that type of simulation produces glasses under high pressure which can induce this overestimation in our results. 35 Nevertheless, the overall experimental behavior of elastic properties is well reproduced in our simulations. The trend observed for Young modulus can be mainly due to the increase in the connectivity of the glass network.…”

Section: Glass Elasticitysupporting

confidence: 52%

Computational insights into the structure of barium titanosilicate glasses

et al. 2019

View full text Add to dashboard Cite

Understanding the role of TiO2 in BaO‐TiO2‐SiO2 (BTS) glasses is one of the keys to develop new glasses and glass‐ceramics for different technological applications. For the first time, molecular dynamics simulations were conducted to get new insights into the atomic structure of the BTS glasses and their elastic moduli. Various compositions are studied where SiO2 have been replaced by TiO2. The calculated mechanical properties of our models are observed to depend linearly on TiO2 content. However, the structure‐induced changes are far from such dependence. The structural results indicate that BTS glasses are mainly built on four types of basic units: SiO4, TiO4, TiO5 and TiO6. This high structural heterogeneity induced by the three coordination states of Ti is found to have an impact on the medium range order by increasing the rings number, the polymerized regions, and by transforming Q3‐Q4 and Q2 without neglecting the increase in Q5 and Q6 species. Those structural modifications of the BTS glass network features have been found to be consistent with available experimental data.

show abstract

“…The densification increases gradually with applied pressure between a lower elastic pressure limit and an upper saturation pressure. For the hydrostatic compression of silica the lower threshold is $10 GPa; saturation occurs at $25 GPa and at a densification of 21% [7]. Structural compaction can also be induced by irradiation from various sources (including electrons); the maximum densification is limited to 3% [8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%