Silica glass under pressure: a view from first principles calculations

Simona Ispas (1)

1 L2C - Laboratoire Charles Coulomb

The vibrational properties of silica glass under pressure have been intensively studied experimentally during the last four decades, in particular using Raman spectroscopy. However there are few theoretical studies of the evolution of the vibrational properties under pressure. By using a combination of classical and first principles molecular simulations, we have generated a series of structural models for amorphous silica for pressures between 0 and 12 GPa. Further, their vibrational density of states and infrared spectra have been calculated within the density functional theory framework, known to reliably predict these properties, at least at zero pressure. In this talk, we will discuss the evolution of the vibrational features (band positions and peak intensities) of our models under pressure, focusing on their correlation to the structural changes as well as to the variation of their elastic moduli.

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

Simona Ispas. Silica glass under pressure: a view from first principles calculations. 2018 Glass & Optical Materials Division Annual Meeting, May 2018, San Antonio, United States. ⟨hal-01938528⟩