Structure-induced order-disorder transformation in Cd-Na liquid alloys

The origins of the S-shaped entropy of mixing and order-disorder transformation in Cd-Na liquid alloys have been investigated within a first-principle approach of a pseudopotential perturbation scheme with the Gibbs-Bogoliubov variation technique. We find that the deepening of the structure part of the entropy around the stoichiometric composition (C _Na ≈ 0.33) is responsible for the S-shaped entropy and suggests the existence of short-range order in the liquid state. The role of the local-field correction function, G(q), of conduction electrons on the entropy of mixing is examined. The impact of G(q) on partial structure factors is more visible towards low q (q → 0) than at higher q.