PHASE EQUILIBRIA IN TERNARY SYSTEM CsCl-CsBr-Cs2MoO4 AND THE ELEMENTS OF ITS TERMINATED

Abstract

The methods of physical-chemical analysis is widely used for the development of new compositions of functional materials for various purposes. The alkali halides have found most widespread use in the industry. Mixtures based on them are used as electrolytes for chemical sources of current, heat storage materials, environments for growing single crystals uxes for metal welding and soldering, as compositions for salt baths and others. Other salts, such as molybdates, tungstates, chromates etc., are often injected into the composition of salt systems besides halides. Their study is of practical interest. So as a research object has been selected ternary system from chloride, bromide and molybdate cesium and its unexplored elements of faceting. The studies were conducted using a differential thermal analysis. The prognosis of the population and composition of the crystallizing phases in the unstudied elements of the selected object of the study given in the present work. Triangle compositions of the ternary system CsCl–CsBr–s2MoO4 consists of the three binary systems: CsCl–CsBr, CsCl–Cs2MoO4, CsBr–Cs2MoO4. The binary system CBr–Cs2MoO4 has not been studied. In the CsBr-Cs2MoO4 system predicted eutectic formation as the system CsCl–Cs2MoO4 relates to eutectic systems. Two variants are possible liquidus topology in the ternary system CsCl–CsBr–Cs2MoO4. In the case of the collapse of the binary solid solution CsClxBr1–x with the formation limited solid solutions based on CsCl and CsBr in ternary system formed eutectic. In the case of the stability of a binary solid solution CsClxBr1–x with a minimum inside the ternary system minimum is predicted on of invariant equilibrium curve connecting the bynary eutectic systems CsCl–Cs2MoO4 and CsBr–Cs2MoO4 The experimental study of the ternary system from the chloride, bromide and molybdate cesium and binary system from the bromide and molybdate cesium are shown in the present work. Additional studies the CsCl–Cs2MoO4 byli system conducted to clarify the data visually polythermal analysis by differential thermal analysis. The liquidus system is represented by three branches of crystallization. The binary system is a eutectic. The melting temperature and the composition of the eutectic e1have been rened over the intersection of the branches of the primary crystallization. The melting point of eutectic 563 degree Celsius, the composition – 40.0 % Cs2MoO4 + 60.0 % CsCl. Eutectic composition corresponds to the invariant equilibrium – Lb-CsCl+a-Cs2MoO4. The experimental study of a bynary system CsBr–Cs2MoO4 given in the article. The liquidus of the system is represented by two branches of crystallization: cesium bromide and cesium molibdate. The binary system is a eutectic. The composition and the temperature of eutectic melting point e2 were determined by the intersection of the primary crystallization of branches: 584 degree Celsius; 49.0 % Cs2MoO4 + 51.0 % CsBr. Eutectic composition corresponds the invariant equilibrium – LiCsBr+b-Cs2MoO4. The experimental study of a ternary system CsCl–CsBr–Cs2MoO4 given in the article. The liquidus the ternary system CsCl-CsBr-Cs2MoO4 represented by three crystallization elds: b- and a-Cs2MoO4 and the continuous series of solid solutions CsClxBr1-x. The minimum point of the system is conditionally invariant with the phase equilibrium L􀒙a-Cs2MoO4 + CsClxBr1-x. The composition of a minimum 22.5 % CsCl + 35.0 % CsBr + 42.5 % Cs2MoO4 with the melting temperature 556 degree Celsius.

Keywords

• phase equilibria
• point of invariant equilibria
• continuous series of solid solutions
• line of the monovariantequilibria
• differential thermal analysis