Investigation of Phase Equilibria in the Ternary Systems RbCl–RbI–Rb2CrO4 and CsCl–CsI–Cs2CrO4

Abstract

By differential thermal analysis, the ternary systems MCl–MI–M2CrO4 (M = Rb, Cs) were studied, and the characteristics (melting points, concentrations of components) of alloys at invariant equilibrium points of the systems were determined. The studied systems are systems of the same type that form by varying the alkali metal cation with increasing atomic number of the cation. In all the binary systems constituting the ternary systems, eutectics form. Based on analyzing the faceting elements, it was assumed that eutectics form in the ternary systems. Low-melting eutectic mixtures of alkali-metal halides and chromates are chemically stable even in the molten state and have low viscosity and low volatility, which makes them suitable for using as heat-storage materials or electrolytes for chemical current sources. Consideration of the systems MCl–MI–M2CrO4 (M = Li, Na, K, Rb, Cs) showed that the varying alkali metal cation in them does not affect the morphology of the liquidus.