Thermal stability and far infrared transmitting property of GeTe4-AsTe3-AgI glasses and glass-ceramics

Abstract The present GeTe 4 -AsTe 3 -AgI glasses extend the optical window to up to 25 μm and its glass-forming region has been explored for practical applications. Their structure, glass-forming ability, thermal stability, infrared transmitting properties were investigated. The results reveal that the GeTe 4 -AsTe 3 -AgI glasses exhibit a large glass-forming region situated around the GeTe 4 -rich domain. Raman analysis confirms the formed [GeTe 3 I] and [AsTe 2 I] units are mainly responsible for the improvement in glass-forming ability. The optimum 40GeTe 4 -30AsTe 3 -30AgI glasses exhibit a large optical window extending from 2 to 25 μm while being stable enough toward crystallization to permit the preparation of fibers and molded lenses. Under proper annealing at 150 °C, 40GeTe 4 -30AsTe 3 -30AgI glass-ceramics, with high mechanical and thermal properties while still keeping the IR transmittance unchanged, were obtained for the first time.