Factors Affecting Microscopic Basicity of Silicate Glasses from the Perspective of O1s Binding Energy

Abstract

The factor affecting the microscopic basicity of oxygen in the SiOSi bond are investigated on the basis of the O1s binding energy measured by X‐ray photoelectron spectroscopy (XPS). The samples used are SiO2, Na2OSiO2, CaOSiO2, CaOMgOSiO2, and CaOAl2O3SiO2. For analysis on clean surfaces, samples are finally prepared by fracturing in a vacuum in an XPS system. From the O1s spectra, derived are the centers of gravity of the O1s spectra and the binding energies of O1s in the SiOSi, SiOAl, AlOAl, SiONa, SiOCa, and SiOMg bonds. A good linear relationship is found between the center of gravity of the O1s spectra and the optical basicity, suggesting that the center of gravity of the O1s spectra is a reasonable basicity index of silicate glasses used in this work. It is also found that there is a linear relationship between the binding energy of O1s in the SiOSi bond and the optical basicity, irrespective of the glass systems. This indicates that the experimental microscopic basicity of oxygen in SiOSi bond is affected not only by the first neighboring ions of oxygen but also by the composition of the sample.