Entropy of mixing of compound forming liquid binary alloys

Entropy determination for mixtures in the adiabatic grand-isobaric ensemble

The entropy change that occurs upon mixing two fluids has remained an intriguing topic since the dawn of statistical mechanics. In this work, we generalize the grand-isobaric ensemble to mixtures and develop a Monte Carlo algorithm for the rapid determination of entropy in these systems. A key advantage of adiabatic ensembles is the direct connection they provide with entropy. Here, we show how the entropy of a binary mixture A–B can be readily obtained in the adiabatic grand-isobaric ( μA, μB, P, R) ensemble, in which μA and μB denote the chemical potential of components A and B, respectively, P is the pressure, and R is the heat (Ray) function, that corresponds to the total energy of the system. This, in turn, allows for the evaluation of the entropy of mixing and the Gibbs free energy of mixing. We also demonstrate that our approach performs very well both on systems modeled with simple potentials and with complex many-body force fields. Finally, this approach provides a direct route to the determination of the thermodynamic properties of mixing and allows for the efficient detection of departures from ideal behavior in mixtures.

A systematic study of segregation for Zn(x)Bi(1-x) liquid binary alloys

We have investigated the segregating properties of Zn(x)Bi(1-x) liquid binary alloys through the thermodynamic route that involves both energy of mixing and entropy of mixing. The perturbation approach is used for effective numerical calculations. Results of our calculations agree well with corresponding experimental data for energy and entropy of mixing in the mixed state. The final prediction of segregating properties such as critical concentration and critical temperature also matches reasonably well with experimental data. Most importantly, both energy of mixing and entropy of mixing have produced almost same values for critical concentration and critical temperature of segregation and thus confirm the reliability of the present approach.

Entropy of mixing for Ag(x)In(1-x) and Ag(x)Sn(1-x) liquid binary alloys

The entropy of mixing for Ag(x)In(1-x) and Ag(x)Sn(1-x) liquid binary alloys has been systematically investigated by using the perturbation theory. The interionic interactions as one of the basic ingredients are described by a local model pseudopotential. Since the metals forming the concerned alloys are less simple in nature the effect of the sp-d hybridization is appropriately taken into account through the interionic interactions. Results of our calculations across the full range of Ag concentrations are found to be good in agreement with the available experimental data.