  BaTiS3, a quasi-1D complex chalcogenide, has gathered considerable scientific
and technological interest due to its giant optical anisotropy and electronic
phase transitions. However, the synthesis of high-quality BaTiS3 crystals,
particularly those featuring crystal sizes of millimeters or larger, remains a
challenge. Here, we investigate the growth of BaTiS3 crystals utilizing a
molten salt flux of either potassium iodide, or a mixture of barium chloride
and barium iodide. The crystals obtained through this method exhibit a
substantial increase in volume compared to those synthesized via the chemical
vapor transport method, while preserving their intrinsic optical and electronic
properties. Our flux growth method provides a promising route towards the
production of high-quality, large-scale single crystals of BaTiS3, which will
greatly facilitate advanced characterizations of BaTiS3 and its practical
applications that require large crystal dimensions. Additionally, our approach
offers an alternative synthetic route for other emerging complex chalcogenides.
