Neutron scattering study of the vibrations in vitreous silica and germania.
The incoherent approximation for the determination of the vibrational density of states of glasses from inelastic neutron or x-ray scattering data is extended to treat the coherent scattering. The method is applied to new room temperature measurements of vitreous silica and germania on the thermal time-of-flight spectrometer IN4 at the High Flux Reactor in Grenoble. The inelastic dynamic structure factor at the boson peak turns out to agree reasonably well with simulation results, but the long-wavelength fraction exceeds the expectation of the Debye model, in particular, in germania.
Fabiani
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CEA LETI Minatec Departement des Technologies pour la Biologie et la Sante, 38054 Grenoble Cedex 9, France. elisa.fabiani@cea.fr
Fontana
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Buchenau
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D005139:Eyeglasses; D005857:Germanium / Q000737:chemistry*; D033363:Neutron Diffraction; D012822:Silicon Dioxide / Q000737:chemistry*; D014732:Vibration
D005857:Germanium; D012822:Silicon Dioxide