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 57Fe2O3, and were Fourier transformed to yield the real space total correlation function, T(r). In addition, the Fe2+ fraction was measured using Mössbauer spectroscopy, and the distribution of silicate structural unit species present in the base glass was obtained from 29Si 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 ΔTFe(r). Conclusions are drawn with respect to both the structure of the base glass and the environment of the Fe2+/Fe3+ cations.