Thermodynamic properties of liquid Te-Ga and Te-Tl alloys

We have used a statistical mechanics model based on the assumption of compound formation in binary alloys to study the bulk and surface properties of Te-Ga and Te-Tl liquid alloys. The assumption of appropriate complexes, specifically, equiatomic TeGa for Te-Ga alloys and Tl4Te for Te-Tl in conjunction with the model enables us to gain a better insight into the nature of order in the two liquid alloys. Using the basic interaction parameters that characterize the model, we have been able to compute the bulk thermodynamic properties of the alloys. Essentially, from our calculations, we are able to show that the Te-Ga liquid alloy is one that undergoes an order-disorder transformation depending on the proportion of Te in the alloy. The Te-Tl system on the other hand exhibits compound formation over the whole composition range. With regards to surface properties, at lower concentration Te segregates more to the surface in Te-Ga alloys than in Te-Tl, however, at higher concentrations the two alloys exhibit quantitatively similar features in the composition dependence of surface concentration. (C) 2003 Elsevier B.V. All rights reserved.