Structure of Ca-Sr-Ba Sodium-Borosilicate Glasses according to B-11 and Si-29 NMR Spectroscopy

摘要

The structure of borosilicate glasses is studied with B-11 and Si-29 NMR spectroscopy in order to investigate the influence of replacement of Na2O by oxides of alkali earth metals on their local structure. The quantitative data are analyzed with respect to their correspondence to the criterion of the average charge of the structural unit. The reasons for the deviation between the experimental results and this criterion are considered. It is shown that, in the case of glass devoid of borate structural units with nonbridging oxygen atoms, the corrected contents of these units are consistent with the predictions of thermodynamic modeling of the structure and properties of oxide glasses.