Effects of the iodine incorporation on the structure and physical properties of Ge-Sb-Se chalcogenide glasses

(100-x)(Ge23Se67Sb10)-xI (x = 0, 3, 5, 7, 10 wt%) chalcohalide glasses were prepared by the traditional melt-quenched method. The structure and physical properties were analyzed by using XRD, TMA, FTIR and Vickers hardness tester. It was found that the glass structure trends to crystallization with increase of iodine content. The values of infrared transmittance decrease from 62% to 35% in the range of 2.5-16 μm with increasing iodine content. The density decreases from 4.62 ± 0.3 g cm−3 to 4.31 ± 0.3 g cm−3, the hardness decreases from 164.9 ± 0.5 kg mm−2 to 154.6 ± 0.5 kg mm−2. The glass transition point Tg decreases from 267 °C to 205 °C, while the thermal expansion coefficient increases with iodine content.