Compositional dependence of physical and structural properties in (Ge1−xGax)S2 chalcogenide glasses

Glassy and partially crystallized samples of (Ge1−xGax)S2 (0 mol% ≤ x ≤ 50 mol%) were prepared and investigated for the Ga effect on their physical and structural properties. For low Ga content (0 mol% ≤ x ≤ 30 mol%), homogeneous glassy samples were prepared and present good physical properties, such as high glass transition temperature (>400 °C) and Vickers hardness (>2.60 GPa). With the Ga substitution for Ge, the thermal stability of samples decreases, leading to the precipitation of α-Ga2S3 crystallites when x > 40 mol%. Structural evolution of (Ge1−xGax)S2 samples was investigated by Raman spectra and X-ray diffraction techniques. The correlation between the physical properties and structural evolution was established.