RAMAN SPECTRA OF SILICA AND BINARY SODO-SILICATE GLASSES FROM FIRST PRINCIPLES CALCULATIONS

Simona Ispas (1)

1 L2C - Laboratoire Charles Coulomb

Silicate glasses possess a central role in glass technology due to their multiple applications ranging from optical devices to the immobilization of nuclear waste. In this context, an accurate theoretical modeling of their spectra can be proven to be invaluable in order to optimize their performance and tailor their fabrication method to match requirements for future applications. 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 silica glass, within the density functional theory framework. At zero pressure, we have found a good agreement with the experimental spectra as well as to previous calculations reported in the literature. Modifications of the Raman spectra under pressure have been found to be in agreement with experimental data. We will equally present preliminary results on simulated Raman spectra of a binary sodo- silicate glass. We focus on the effect of local structural units, such as SiO 4 tetrahedra and their interconnection, alongside the role of sodium atom content in order to assign the corresponding bands. The obtained information can be then used in order to help to interpret the experimental spectra obtained for more complex silicate glasses.

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

Simona Ispas. RAMAN SPECTRA OF SILICA AND BINARY SODO-SILICATE GLASSES FROM FIRST PRINCIPLES CALCULATIONS. 14th International Conference on the Physics of Non-Crystalline Solids, Sep 2015, Niagara Falls, United States. ⟨hal-01938467⟩