Zobrazeno 1 - 10
of 362
pro vyhledávání: '"Vacher, R."'
Autor:
Wang, P. -J., Huynh, A., Hung, T. -C., Sheu, J. -K., Lafosse, X., Lemaitre, A., Perrin, B., Rufflé, B., Vacher, R., Sun, C. -K., Foret, M.
Many theories predict a quartic acoustic attenuation increase at sub-THz frequencies in glassy media for the excess vibrational modes known as the boson peak anomaly. Here by introducing phase-sensitive acoustic spectroscopy techniques with a THz ban
Externí odkaz:
http://arxiv.org/abs/2310.11832
Publikováno v:
Rev. Sci. Instrum. 82, 113110 (2011)
We present a new optical arrangement which allows to avoid the broadening by finite aperture in Brillouin spectroscopy. In this system, all the rays scattered at the same angle by the whole scattering volume are collected on a single pixel of the are
Externí odkaz:
http://arxiv.org/abs/1109.3531
Publikováno v:
Phys. Rev. Lett. 104, 067402 (2010)
The position and strength of the boson peak in silica glass vary considerably with temperature $T$. Such variations cannot be explained solely with changes in the Debye energy. New Brillouin scattering measurements are presented which allow determini
Externí odkaz:
http://arxiv.org/abs/1001.4347
Publikováno v:
Phys. Rev. B 76, 054210 (2007)
Hyper-Raman scattering has been measured on vitreous boron oxide, $v-$B$_2$O$_3$. This spectroscopy, complemented with Raman scattering and infrared absorption, reveals the full set of vibrations that can be observed with light. A mode analysis is pe
Externí odkaz:
http://arxiv.org/abs/0711.1782
Publikováno v:
Phys. Rev. Lett. 100, 015501 (2008)
Experimental results on the density of states and on the acoustic modes of glasses in the THz region are compared to the predictions of two categories of models. A recent one, solely based on an elastic instability, does not account for most observat
Externí odkaz:
http://arxiv.org/abs/0711.0461
Publikováno v:
Phys. Rev. Lett. 96, 105502 (2006).
Hyper-Raman scattering spectra of vitreous B$_2$O$_3$ are reported and compared to Raman scattering results. The main features are indexed in terms of vibrations of structural units. Particular attention is given to the low frequency boson peak which
Externí odkaz:
http://arxiv.org/abs/cond-mat/0510754
Publikováno v:
J. Non-Cryst. Solids 352, 4589 (2006)
The dynamic structure factor of lithium-diborate glass has been measured at several values of the momentum transfer $Q$ using high resolution inelastic x-ray scattering. Much attention has been devoted to the low $Q$-range, below the observed Ioffe-R
Externí odkaz:
http://arxiv.org/abs/cond-mat/0510714
Publikováno v:
Phys. Rev. Lett. 96, 045502 (2006)
High frequency sound is observed in lithium diborate glass, Li$_2$O--2B$_2$O$_3$, using Brillouin scattering of light and x-rays. The sound attenuation exhibits a non-trivial dependence on the wavevector, with a remarkably rapid increase towards a Io
Externí odkaz:
http://arxiv.org/abs/cond-mat/0506287
This series discusses the origin of sound damping and dispersion in glasses. In particular, we address the relative importance of anharmonicity versus thermally activated relaxation. In this first article, Brillouin-scattering measurements of permane
Externí odkaz:
http://arxiv.org/abs/cond-mat/0505558
The temperature dependence of the frequency dispersion in the sound velocity and damping of vitreous silica is reanalyzed. Thermally activated relaxation accounts for the sound attenuation observed above 10 K at sonic and ultrasonic frequencies. Its
Externí odkaz:
http://arxiv.org/abs/cond-mat/0505560