Structural insights for the International Simple Glass by combining X-ray absorption spectroscopic analysis and atomistic modelling

Abstract

Structural investigation of disordered systems rely mainly on atomistic simulations or are inferred from experimental techniques like NMR or X-ray absorption spectroscopy, but there is still a gap when trying to combine them. Based on the structural study of the borosilicate glass ISG, we used a combination of 11B NMR, X-ray and neutron diffraction, XANES, EXAFS and EPSR atomistic modelling to further investigate the local and medium range order of this specific glass. In particular, we present improved EXAFS fits by using local Zr environment extracted from EPSR simulations, which highlight the role of SiO4, BO3 and BO4 structural units, and the charge sharing role of alkalis in the Zr environment. We also show that multiple scattering paths are likely to be present in EXAFS data for this kind of glass, which leads to important conclusions regarding Zr environment.