The environment of Fe2+/Fe3+ cations in a soda-lime-silica glass

The neutron diffraction isotopic substitution technique is employed to investigate the environment of Fe2+/Fe3+ cations in a soda lime silica glass. Data were recorded for three samples; the base glass, the base glass incorporating natural Fe2O3 and a similar glass containing isotopically-enriched (Fe2O3)-Fe-57, and were Fourier transformed to yield the real space total correlation function, T(r). In addition, the Fe2+ fraction was measured using Mossbauer spectroscopy, and the distribution of silicate structural unit species present in the base glass was obtained from Si-29 magic angle spinning (MAS) NMR spectroscopy. The first co-ordination shells of the Fe2+/Fe3+ cations were investigated via a peak fit to the isotopic difference correlation function Delta T-Fe(r). Conclusions are drawn with respect to both the structure of the base glass and the environment of the Fe2+/Fe3+ cations.