Iron enriched peraluminous glasses: incorporation limit and effect of iron on glass transition temperature and viscosity
Abstract
This study investigates the effect of iron oxide Fe2O3 on the homogeneity, viscosity, and glass transition temperature (Tg) of peraluminous glasses. As-quenched glass samples elaborated at 1350°C show an incorporation limit around 17.5 wt% of Fe2O3 (10.4 mol%), while slowly cooled glass samples show a limit of 7.5 wt% of Fe2O3 (4.25 mol%). Iron in the peraluminous glasses investigated was detected under three configurations: 6-fold coordinated 6Fe3+ in majority, 4-fold coordinated 4Fe3+ and 6-fold coordinated 6Fe2+. It was observed that Fe2O3 addition has a strong fluidifying effect on peraluminous glasses and tends to slightly decrease the glass transition temperature Tg, depending on its thermal history.