Dynamics of a hydrogenated silica xerogel: A neutron scattering study

Fontana, A.; Orsingher, L.; Rossi, F.; Buchenau, U.

doi:10.1103/physrevb.74.172304

Cited by 5 publications

(1 citation statement)

References 22 publications

(25 reference statements)

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“…At first sight it would seem that the influence of T f would explain the differences in presented experimental data but it is necessary to have further consideration: even the different content of OH bonds can change the excess of density of states [17,18] and moreover we found a linear correlation between the Brillouin shift and the OH content of our samples (see inset (a) of figure 3). This non-trivial dependence can help us to assess another microscopic origin of different intensities and positions of BP.…”

Section: Discussionmentioning

confidence: 83%

The influence of the fictive temperature and the OH content on the dynamical properties of vitreous silica: comparison of Raman, Brillouin, and neutron scattering spectra

Caponi¹,

Fontana²,

Mattarelli³

et al. 2007

J. Phys.: Condens. Matter

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We have performed new inelastic light and neutron scattering experiments on different samples of vitreous silica: Puropsil, Spectrosil, Tetrasil, Suprasil and Heralux commercial grade samples have been investigated by means of Raman and Brillouin light scattering and inelastic neutron scattering experiments.We have found significant changes in the density of states and in the sound velocity, which can be attributed to differences both in the fictive temperature and in the OH bonds present in the different samples.

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Section: Discussionmentioning

confidence: 83%

The influence of the fictive temperature and the OH content on the dynamical properties of vitreous silica: comparison of Raman, Brillouin, and neutron scattering spectra

Caponi¹,

Fontana²,

Mattarelli³

et al. 2007

J. Phys.: Condens. Matter

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Damping of sound waves in the terahertz range and strength of the boson peak

Bove

Petrillo

Fontana

et al. 2008

The Journal of Chemical Physics

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By applying a new two-step line-shape analysis to inelastic neutron and x-ray scattering spectra of glassy systems, we were able to resolve the acoustic excitations from the low-frequency excess modes and to accurately estimate the damping of sound waves in the terahertz frequency range. Using this approach, we estimated the damping parameter for terahertz acoustic waves in a wide class of chemically different glasses and did a quantitative comparison of the results with prediction of theoretical models. By comparing the estimates of the mean-free path of the acoustic modes in different glasses and the corresponding boson peak strengths, we show the existence of a simple correlation between these two quantities. The relationship between attenuation of the terahertz acoustic modes, strength of the boson peak, and fragility is discussed.

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Vibrational dynamics of permanently densified GeO2 glasses: Densification-induced changes in the boson peak

Orsingher

Fontana

Gilioli

et al. 2010

The Journal of Chemical Physics

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Vitreous GeO(2), one of the main prototypes of strong glasses, was densified at several pressures up to 6 GPa, achieving more than 20% of densification. The density dependence of the vibrational density of states and of the low temperature properties of these glasses was investigated by means of inelastic neutron scattering and calorimetric measurements. With increasing density, both the boson peak and the bump in c(p)/T(3) versus T plot exhibit variations which are stronger than the elastic medium expectation. If one reduces the measured spectra to a common master curve, one finds that this is only possible for the densified samples; the first densification step has an additional effect, similar to other cases in the literature. Nevertheless, the existence of a master curve for the three densified samples proves that the total number of excess modes remains constant on further densification. The experimental data are discussed in the framework of different theoretical models.

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Dynamics of a hydrogenated silica xerogel: A neutron scattering study

Cited by 5 publications

References 22 publications

The influence of the fictive temperature and the OH content on the dynamical properties of vitreous silica: comparison of Raman, Brillouin, and neutron scattering spectra

The influence of the fictive temperature and the OH content on the dynamical properties of vitreous silica: comparison of Raman, Brillouin, and neutron scattering spectra

Damping of sound waves in the terahertz range and strength of the boson peak

Vibrational dynamics of permanently densified GeO2 glasses: Densification-induced changes in the boson peak

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