Determination of Fe3+ sites in a NaFeSi2O6 glass by neutron diffraction with isotopic substitution coupled with numerical simulation

Abstract

Isotopic substitution in neutron diffraction combined with empirical potential structure refinement simulations has been employed to probe the sites occupied by Fe3+ and Fe2+ in a NaFeSi2O6 glass. This study reveals the presence of two populations of Fe3+ sites. 95% of Fe3+ is in tetrahedral sites (dFe3+–O=1.866±0.001Å), as the remainder ferric iron and ferrous iron (∼20% of total Fe) are five coordinated.