First-principles calculation of Raman spectra of amorphous silica: effect of hydrostatic pressure on the vibrations

Simona Ispas (1) , Thomas Fajoux (1) , Bernard Hehlen (1)

1 L2C - Laboratoire Charles Coulomb

The vibrational properties of silica glass have been intensively studied experimentally and theoretically during the last four decades. However there are few theoretical studies of the evolution of the vibrational properties under pressure. We have calculated the parallel and perpendicular Raman spectra of the vitreous silica. The study has been carried out using first principles calculations within the density functional theory framework. The calculated spectra at ambient pressure are in good agreement with the experimental ones as well as with previous calculations reported in the literature. The modifications of the Raman spectra under pressure also reproduce the experimental data. A preliminary analysis of the resulting structural modifications and their correlations with the changes seen in the spectra will be reported.

Domaines: Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]; Science des matériaux [cond-mat.mtrl-sci]

Simona Ispas, Thomas Fajoux, Bernard Hehlen. First-principles calculation of Raman spectra of amorphous silica: effect of hydrostatic pressure on the vibrations. Réunion SIMADES VI, Nov 2014, Bagnols-sur-Cèze, France. ⟨hal-01937672⟩