%0 Conference Paper
%F Oral 
%T Ab-Initio modeling of vibrational spectra of silicate glasses and decomposition into principal structural components.
%+ Laboratoire Charles Coulomb (L2C)
%+ Service d'Etudes du Comportement des Matériaux de Conditionnement (SECM)
%A Kilymis, Dimitrios
%A Hehlen, Bernard
%A Peuget, S.
%A Delaye, Jean-Marc
%A Ispas, Simona
%< sans comité de lecture
%Z L2C:17-324
%B Glass & Optical Material Division, Annual Meeting 2017 (GOMD)
%C Waikoloa - Hawaï, United States
%8 2017-05-21
%D 2017
%Z Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn]Conference papers
%X Density functional theory is used to calculate the vibrational properties of pure silica and sodo-silicateglasses with 20, 25, and 33 mol% of Na2O. The infrared and Raman spectra are calculated and the full responses aredecomposed into principal structural components (PSC). Those are for example the SiO4n--tetrahedra with n nonbrigdingoxygens defining the Qn-species at the origin of the structured feature at high frequency, and the Si-O-Sibridges leading the broad Raman R-band at intermediate frequencies. Our results confirm that Si-O-Si bending inbridges with large angle vibrate preferentially at lower frequencies than those with low angle. In addition, the spectralresponse of the Q2-species is bimodal and overlaps with that of the Q3, while the Q4 response covers almost all ofthe spectral range of the Qn-band. The ab-initio individual spectral responses of the PSC are used to reconstruct theexperimental Raman responses. Contrary to the commonly used multi-Gaussian decomposition, this approachprovides unambiguous band-assignments and hence a more accurate way to probe the structural and chemicalproperties of glasses from their spectroscopic signature.
%G English
%L hal-01937865
%U https://hal.science/hal-01937865
%~ CEA
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ UM-2015-2021