Ferric-ferrous equilibrium in low-iron sodium-silicate glasses

摘要

M(o)ssbauer and Electron paramagnetic resonance measurements have been performed on iron-containing sodium-silicate glasses with Na2O/SiO2 ratio equal to 19/81 and Fe2O3 content up to 7 wt. %.. The influence of total iron content on local environment of ferric and ferrous ions and ferric/ferrous ratio were investigated by the combination of both spectroscopic methods. Fe2+ behaves as a network modifier occupying predominantly octahedral sites while Fe3+ is a network former occupying tetrahedral sites. It was also observed "solated" Fe3+ (broad hyperfine magnetic splitting) in low-iron samples by M(o)ssbauer spectroscopy. Ferrous/ ferric ration decreases with increasing total iron content.