High-temperature solid–vapor and liquid–vapor transitions in binary and ternary chalcogenides La2S3, MoS2, Mo2S3 and LiInSe2

High heating rate thermo-microscopic analysis, analytical atomic-emission technique with inductively coupled plasma and differential dissolution method have been used to investigate solid–liquid and solid–liquid–vapor transitions of refractory chalcogenides La2S3, MoS2, Mo2S3 and LiInSe2. The techniques were effective in determining the total pressure and vapor phase composition over the compounds in large temperature and pressure ranges. As a result, for compounds that evaporate incongruently, the melting points corresponding to their strict stoichiometry, the decomposition pressure–temperature relations, and other new results of the T–x phase diagrams for the La3S4–La2S3, Mo–MoS2, and Li2Se–LiInSe2 systems were obtained.