Determination of phase fields in the CsBr-Cs2ZnBr4-Cs2CdBr4-Cs2HgBr4 quaternary system

Phase equilibria in the CsBr-Cs₂ZnBr₄-Cs₂CdBr₄-Cs₂HgBr₄ quaternary system were studied by differential thermal analysis. The CsBr-Cs₂ZnBr₄-Cs₂HgBr₄ ternary system has a ternary eutectic, E ₁, at ～83 mol % Cs₂HgBr₄, 2 mol % Cs₂ZnBr₄, and 15 mol % CsBr with a melting point of ～415°C. The CsBr-Cs₂ZnBr₄-Cs₂CdBr₄ ternary system has a ternary eutectic, E ₂, at ～53.5 mol % Cs₂CdBr₄, 1.5 mol % Cs₂ZnBr₄, and 45 mol % CsBr with a melting point of ～450°C. The polythermal section Cs₃ZnBr₅-Cs₂CdBr₄-Cs₂HgBr₄ in the CsBr-Cs₂ZnBr₄-Cs₂CdBr₄-Cs₂HgBr₄ quaternary system was constructed and investigated. This section is a quasi-ternary system and is characterized by the formation of regions of solid solutions Cs₂Zn _x Cd _y Hg_{1?x ? y} Br₄ and solid solutions based on Cs₃ZnBr₅. The liquidus surface of the quaternary system consists of three fields of primary crystallization of cesium bromide, a solid solution Cs₂Zn _x Cd _y Hg_{1?x ? y} Br₄, and a solid solution based on Cs₃ZnBr₅.