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

Glassy and partially crystallized samples of (Ge1-xGax)S-2 (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 degrees C) and Vickers hardness (> 2.60 GPa). With the Ga substitution for Ge, the thermal stability of samples decreases, leading to the precipitation of alpha-Ga2S3 crystallites when x > 40 mol%. Structural evolution of (Ge1-xGax)S-2 samples was investigated by Raman spectra and X-ray diffraction techniques. The correlation between the physical properties and structural evolution was established.