Phase Equilibria in the LiF–K₂CrO₄–KCl–KBr Stable Tetrahedron of the Li⁺,K⁺||F^–,Cl^–,Br^–,\({\text{CrO}}_{4}^{{2 - }}\) Quinary Reciprocal System

The quinary reciprocal system Li⁺,K⁺||F^–,Cl^–,Br^–, \({\text{CrO}}_{4}^{{2 - }}\) contains the LiF–KCl–KBr–K₂CrO₄ stable tetrahedron, which is the subject of this study. We have predicted the number and composition of phases crystallizing in the stable elements of the corresponding phase tree with allowance for bounding elements, including a continuous solid solution series (CSSS). The system has been studied by differential thermal analysis and X‑ray diffraction. The results indicate that there are no invariant equilibrium points in the stable elements of the system and demonstrate stability of the solid solutions containing chloride and bromide ions.