Configurational entropies of mixing in solid alloys

Entropy becomes an increasingly important contributor to the Gibbs energy at high temperatures with both non-configurational and configurational contributions to be considered. Some examples of where configurational entropies alone are important in determining the domain of phase stability of a solution phase are given. In phenomenological calculations, the modeling of configurational entropy should allow for short range order and be readily applicable to multicomponent systems. The use of Fowler-Yang-Li transforms is important in this regard by providing the opportunity for changing the functional variables in cluster calculations of the Gibbs energy from cluster probabilities or correlation functions to the considerably fewer point probabilities, just as in the Bragg-Williams approximation.