Low‐Temperature Synthesis of Refractory Glasses in the La ₂ S ₃ ‒Ga ₂ S ₃ System

ABSTRACT Ga‒La‒S glasses have received much attention due to their broad infrared transparency, high rare‐earth solubility, and high thermal resistance relative to other chalcogenide glasses. Their high glass transition temperature makes them suitable for application in harsh thermal environments but their synthesis from the melt is experimentally problematic due to fast corrosion and extreme fusion temperatures. We therefore report a low‐temperature route for the synthesis of refractory Ga‒La‒S glass powders through high‐energy ball milling. Systematic calorimetric and spectroscopic characterization is presented across the glass formation range and compared with melt‐quenched glass. It is found that Ga‒La‒S glasses can be easily produced by mechanosynthesis across a broad compositional range but the high specific surface area of ball‐milled glass powder promotes heterogeneous nucleation in gallium‐rich compositions. An FTIR analysis indicates that oxygen impurities brought in by water contamination do not integrate into the glassy network. Raman analysis across the compositional range is consistent with compositional evolution.