Crystallization behavior of 70GeS2–20In2S3–10CsI chalcohalide glass with silver addition

The crystallization behavior of the 70GeS2–20In2S3–10CsI glass introduced with 2 mol% Ag2S system has been studied under non-isothermal condition. The beginning of transmission is shifted toward longer wavelength as a function of annealing temperature. Thermal properties were measured by the differential scanning calorimeter. From the heating rate dependence of crystallization temperature, the activation energy (Ec) for crystallization and the crystallization rate constant (K) were calculated. The K value of 2.44 × 109 for the In2S3 phase is about 28 times larger than the second CP, this is why the controllable crystallization to transparent chalcogenide glass-ceramics with sole In2S3 crystallites can be achieved. By heat treatment with various temperatures, the hardness of the glass enhanced from 204 to 230.8 kg mm−2, while retained the transmittance of the 8–11 μm.