%0 Conference Paper
%F Oral 
%T Polarized Raman spectroscopy of v-SiO2 under rare gas compression
%+ Laboratoire Charles Coulomb (L2C)
%A Weigel, Coralie
%A Foret, Marie
%< avec comité de lecture
%Z L2C:16-321
%B 54th European High Pressure Research Group Meeting (EHPRG 2016)
%C Bayreuth, Germany
%8 2016-09-05
%D 2016
%Z Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]
%Z Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph]
%Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Vibrations [physics.class-ph]Conference papers
%X High-pressure polarized Raman spectra of vitreous silica are measured up to 8 GPa in a diamond-anvil cell at room temperature. The combined use of either a nonpenetrating pressurizing medium—argon—or a penetrating one—helium, allows one to separate density from stress effects on the Raman frequencies. In the framework of a simple central force model, the results emphasize the distinct role played by the shrinkage of the intertetrahedral angle Si-O-Si and the force-constant stiffening during the compression. The polarization analysis further reveals the existence of an additional isotropic component in the high-frequency wing of the boson peak. The pressure dependence of the genuine boson peak frequency is found to be much weaker than previously reported and even goes through a minimum around 2 GPa in remarkable coincidence with the anomalous compressibility maximum of silica.
%G English
%L hal-01909031
%U https://hal.science/hal-01909031
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ UM-2015-2021