Effect of Fluorine on Silicate Network for CaO-CaF₂-SiO₂ and CaO-CaF₂-SiO₂-FeO_x Glasses

Abstract

The chemical state of fluorine and the effect of fluorine addition on the degree of polymerization of silicate network have been investigated for the CaO-SiO₂-CaF₂ and CaO-SiO₂-CaF₂-FeO_x glasses using the X-ray photoelectron spectroscopy (XPS) and Mössbauer spectroscopy measurements. The F1s XPS spectra indicate that the fluorine is dominantly coordinated with calcium rather than silicon. The O1s XPS spectra for the CaO-SiO₂-CaF₂ glasses and the values of Fe²⁺/Fe³⁺ obtained by Mössbauer spectra for the CaO-SiO₂-CaF₂-FeO_x glasses indicate that CaF₂ addition does not depolymerize the silicate network for both systems.