Solvus of KCl:Ba2+ solid solution from flotation measurements of single crystal density

Abstract

The solvus of KCl:Ba2+ is found in the BaCl2 concentration range 0.002 to 0.12 mol% at temperatures from 300 to 550 °C. The decomposition of the solid solution after various regimes of heat treatment is judged by a sharp change in the crystal density determined by the flotation technique. A thermodynamic analysis of the experimental data evaluates the impurity dissolution energy as (1.6 to 2.1) eV, and the vibrational entropy to Sv/k = 10.3 ± 0.8.