Aging in chalcohalide glasses: Origin and consequences

The application of chalcogenide and chalcohalide glasses is limited by their uncontrolled drift in properties over time due to aging processes. In the present work, we perform aging experiments on some chalcohalide glasses in oxidizing, inert and reducing atmospheres and afterwards we measure the elemental concentration depth profiles in the surface layer of the glasses by using secondary neutral mass spectroscopy. The results show that anionic diffusion processes occur in the glasses during aging. The aging process leads to a decrease in microhardness of the studied glasses, which is attributed to both physical aging (i.e., structural relaxation) and chemical aging (i.e., compositional change of the surface layer).