Mechanochemical synthesis and structural characterization of gallium sulfide Ga2S3

Abstract

Crystalline gallium (III) sulfide Ga2S3 samples have been prepared by mechanical-alloying instead of usual heating process. A safe, energy-efficient, and fast process of only 4 ​h of mechanosynthesis led to the formation of polycrystalline Ga2S3 from pure Ga and S as raw materials. X-ray diffraction measurements and Rietveld refinements show that the as-prepared material is a mixture of mainly hexagonal wurtzite-type β-phase (68 ​± ​5 ​wt%; space group P63mc (No. 186)) along with some cubic sphalerite-type γ-phase (32 ​± ​5 ​wt%; space group F-43 ​m (No. 216)). In situ high-temperature X-ray diffraction measurements show that the monoclinic phase (space group Cc (No. 9)) appears at 450 ​°C. Scanning electron microscopy analyses reveal that the morphology of the powder is characterized by aggregates of nanometric particles. Their sizes measured by laser diffraction show a median size around 170 ​nm after 4 ​h of ball-milling.