Physicochemical, optical properties and stability against crystallization of GaxGey-xS100-y (x=0–8; y = 40–42) glasses

•The physicochemical, optical and crystallization properties of GaxGey-xS100-y (x=0–8; y = 40–42) glasses are studied.•The Ga-Ge-S glass annealing results in the formation of the phases of germanium monosulfide, germanium disulfide, and gallium sesquisulfide.•The transparency of glasses in the 8–15 µm region rises with an increase in Ga content.•GaxGe40-xS60 (x = 0–8) and Ga3Ge38S59 glasses have highest stability against crystallization.