Formation and properties of chalcohalide glasses in the As2Se3–GeTe–CuI system

Chalcohalide glasses in the As2Se3–GeTe–CuI system have been prepared. Compositions cover the following range (mol%): As2Se3: 12–100, GeTe: 0–88, CuI: 0–70. Glasses are melted after being sealed at a pressure of about 10−2 Pa and quenched in air. A broad glass-forming region was found based on this ternary system. Some physical properties are discussed in terms of structural variations with compositions. Measurements of glass transition temperature, Tg, microhardness, Hv, fracture toughness, KIc, and thermal expansion coefficient, α, were made. These parameters were found to be proportional to GeTe content. In the As2Se3–CuI glass system, CuI almost eliminated the As–O absorption band in the chalcogenide glasses. The infrared cut-off edges of the present samples were not affected by CuI doping and were mainly determined by Ge–Se or As–Se bonds with bands at 520 or 490 cm−1.