METHOD OF CALCULATION OF THE THERMODYNAMIC PROPERTIES OF BINARY AZEOTROPIC SYSTEMS OF ALKALI-METALS INVOLVING THE USE OF PHASE-DIAGRAMS

A method is proposed for the calculation of the thermodynamic properti es (partial Gibbs' energy, activity of the components) on the boundary curves of the phase diagram for binary azeotropic intermetallic syste ms with a continuous series of solid solutions. The method is based on general equations of thermodynamic equilibrium without any model conc epts of the properties of liquids. The calculation technique employs t he property of mutual binary solutions of alkali metals, which consist s in the existence of a fairly extended ''Raoult'' zone in the region of dilute solutions. The method enables one to simultaneously calculat e the properties on both curves of phase equilibrium, on the liquidus and solidus lines, that is, for liquid and solid solutions. The method is demonstrated for a typical azeotropic intermetallic system with we ak interparticle interaction of Cs-K.