Iron oxide-doped alkali-lime-silica glasses Part 1. EPR investigations

Abstract

Alkali-lime-silica glasses containing iron oxide in a concentration range of 0.1 to 2 mol% were studied by means of EPR spectroscopy. In all glasses, two paramagnetic signals at g = 2.0 and g = 4.3 were obtained. Their intensity strongly depended on the quantity of iron oxide doping and on the type but not on the quantity of alkali. In agreement with experimental results from the literature, the peak at g = 4.3 was attributed to tetrahedrally coordinated Fe^III in C2v symmetry, assuming an alkali ion being coordinated with two oxygens of the tetrahedron. The peak at g = 2.0 was attributed to the occurrence of clusters containing more than two iron atoms.