Depth profile of tin in float glass - a CEMS study

Abstract

The tin content of the bath side of float glass was studied by CEMS (conversion electron Mössbauer spectroscopy). The method provides a high surface sensitivity with an information depth of 1 µm, and allows a distinction between the different valence states of tin. Depth profiles were measured by etching samples stepwise. The tin content decreases rapidly from the surface to the bulk and shows the typical hump between 5 and 10 μm. Sn^^ dominates at the surface, but close to the hump, Sn²⁺ clearly prevails. Still deeper inside, the lower valence states become visible, until the tin concentration falls below the sensitivy limit.