Theoretical calculation of partition coefficients of isovalent impurities with due regard for excess entropy of mixing in the solid solution and the melt

Abstract

AbstractIn analogy with solid solutions, it was found that there is a linear dependence between the magnitude of the enthalpy and excess entropy of mixing in melts which leads to the appearance of a compensation effect in the free excess energy of mixing. Using the derived correlations and on the basis of thermochemical values of enthalpies for the mixing of binary melts, excess entropies of mixing have been evaluated, for most of which experimental values are absent. Partition coefficients for more than 60 impurities during crystallization of alkali halogenides have been determined using an improved method with due regard for heats and excess entropies of mixing in solid solutions and melts. Theoretical values of partition coefficients are compared with experimental ones for which complete summary of determining partition coefficients by various methods is given.