Mossbauer Studies on Iron in Calcium-Silicate Glasses Mossbauer Studies on Iron in Calcium-Silicate Glasses

The behaviours of iron atom in calcium-silicate glasses depending on oxygen partial pressure and basic oxide content have been studied on the basis of Mossbauer spectra. In the glasses containing a large amount of Fe_2O_3, Fe^<2+> ion was always in octahedral site and Fe^<3+> ion behaved as amphoteric one of which site change from octahedral to tetrahedral with increasing of CaO content. The same dependence on partial oxygen pressure as CaO content were observed. In the glasses having small content of Fe_2O_3, Fe^<2+> ion was in both sites of tetrahedral and octahedral although the coordinate state of Fe^<3+> ion was not sufficiently clear.