Neutron Scattering Study of the Low-Frequency Vibrations in Vitreous Silica

Buchenau, U.; Nücker, N.; Dianoux, A.J.

doi:10.1103/physrevlett.53.2316

Cited by 408 publications

(197 citation statements)

References 14 publications

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“…We then proceed with elastic and inelastic scattering from a simple harmonic system. This case has already been discussed more or less explicitely in experimental studies of amorphous solids [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Multiple-scattering effects on smooth neutron-scattering spectra

Wuttke

2000

Phys. Rev. E

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Phys. Rev. E (23feb00), resubmitted (25apr00), cond-mat/0002363) Elastic and inelastic incoherent neutron scattering experiments are simulated for simple models: a rigid solid (as used for normalisation), a glass (with a smooth distribution of harmonic vibrations), and a viscous liquid (described by schematic mode-coupling equations). As long as the spectral distribution of the input scattering law does not vary with wavenumber, it is only weakly distorted by multiple scattering. The wavenumber dependence of the scattering intensity suffers much more.

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Section: Introductionmentioning

confidence: 99%

Multiple-scattering effects on smooth neutron-scattering spectra

Wuttke

2000

Phys. Rev. E

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“…34,35 Excess vibrations were identified also from the analysis of neutron spectra in the form of librations of corner-sharing tetrahedra. 1 The situation in vitreous silica appears thus noticeably different from that in other glasses, like glycerol 22 and sorbitol, 25 where a computation based on Eq. (6) well reproduced the BP shape.…”

Section: Density Of Vibrational States Estimatementioning

confidence: 99%

“…In the frequency range of a few terahertz the reduced density of vibrational states, g(ω)/ω 2 , presents a maximum, which is usually called the boson peak (BP). 1 This feature is ubiquitous in all glasses as revealed by inelastic neutron scattering or Raman spectroscopy. Although studied for many years, the nature of the modes associated with this peak is still a matter of lively debate.…”

Section: Introductionmentioning

confidence: 99%

Elastic anomalies at terahertz frequencies and excess density of vibrational states in silica glass

2011

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We study the temperature dependence of acousticlike excitations measured by means of inelastic x-ray scattering at terahertz frequencies in silica glass. The apparent sound velocity shows, between 300 and 1600 K, the same temperature variation measured, at lower frequencies, by Brillouin light scattering. On the contrary the vibrations at the boson peak (BP) present a much stronger temperature dependence, as indicated by neutron scattering data. The measured dispersion and damping are used to compute the contribution to the vibrational density of states (VDOS) coming from the propagating acousticlike modes. This part of the VDOS accounts only for a fraction of the BP intensity, indicating that other kinds of excitation accumulate in this frequency range. It is consequently not surprising that the BP does not follow the temperature evolution of the Debye frequency, which describes the modification of the continuum medium. Finally we present a comparison between the experimentally accessible quantities and a recently proposed model for the vibrations in glasses, based on the assumption of random spatial variations of the shear modulus [Schirmacher, Europhys. Lett. 73, 892 (2006)].

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“…The elastic continuum approximation for the acoustic excitations breaks down on a mesoscopic wavelength comparable to ξ, where a marked reduction of the sound velocity and strong scattering were observed [10,11]. It has been suggested that the elastic heterogeneity is closely linked to several unusual properties of glasses, which include low-temperature thermal properties [12], an excess vibrational density of states, known as the "Boson peak" [13,14], and anomalous acoustic properties [10,11,[15][16][17]. Theoretical models [18,19] have been proposed to relate the boson peak and the associated thermal and acoustic anomalies to a randomly fluctuating shear modulus.…”

Section: Introductionmentioning

confidence: 99%

Measuring spatial distribution of the local elastic modulus in glasses

Mizuno

Mossa²,

Barrat³

2013

Phys. Rev. E

137

166

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Glasses exhibit spatially inhomogeneous elastic properties, which can be investigated by measuring their elastic moduli at a local scale. Various methods to evaluate the local elastic modulus have been proposed in the literature. A first possibility is to measure the local stress-local strain curve and to obtain the local elastic modulus from the slope of the curve, or equivalently to use a local fluctuation formula. Another possible route is to assume an affine strain and to use the applied global strain instead of the local strain for the calculation of the local modulus. Most recently a third technique has been introduced, which is easy to be implemented and has the advantage of low computational cost. In this contribution, we compare these three approaches by using the same model glass and reveal the differences among them caused by the non-affine deformations.

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Neutron Scattering Study of the Low-Frequency Vibrations in Vitreous Silica

Cited by 408 publications

References 14 publications

Multiple-scattering effects on smooth neutron-scattering spectra

Multiple-scattering effects on smooth neutron-scattering spectra

Elastic anomalies at terahertz frequencies and excess density of vibrational states in silica glass

Measuring spatial distribution of the local elastic modulus in glasses

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