Thermal and optical properties of GeS2-based chalcogenide glasses

Glasses compositions which can be expressed by (100-x)GeS2-xGa2S3 (x=0, 10, 20, 30 mol%), 70GeS2-(30-x)Ga2S3-xCdS (x=0, 10, 15, 20 mol%), and (100-x)GeS2-x[0.5Ga2S3-0.5CdS] (x=0, 10, 20, 30, 40 mol%), were obtained by the melt-quenching technique. Differential scanning calorimetry (DSC) and visible-IR transmission were used to characterize the thermal and optical properties of these glasses, together with refractive index and density measurements. These homogeneous glasses have relatively high glass transition temperatures (338-436 deg. C), good thermal stabilities, broad transparencies (0.45-11.5 μm), large refractive indices (2.01-2.25), and large densities (2.68-3.18 g cm-3). The long-wavelength cutoff edge is found near 12 μm due to the multiphonon Ge-S and Ga-S vibrations. The compositional dependences of selected properties were also discussed by making reference to the structural variation