Preparation and properties of glasses and glass-ceramics based on GeSe2-Sb2Se3 and halides
Résumé
In order to obtain glasses with controllable crystal growth, some new compositions have been studied by introducing halides such as CsI, CsBr, PbI2, CuI, RbI into the well known GeSe2-Sb2Se3 system. Stable compositions, transparent up to 16 μm, having a glass transition temperature higher than 200°C were chosen for ceramisation experiment at different temperatures for different durations. It was found that a high percentage of crystals smaller than 100 nm can be generated and that these microcrystals induce light scattering especially in the short wavelength region. However, glass ceramics may be as transparent as the pure glass from 1 up to 16 μm. The first results show that the glass ceramics demonstrate much better resistance to fracture propagation. To our best knowledge, this is the first publication concerning easily reproducible glass ceramics which are transparent beyond 12 μm.