Thermodynamic Modeling of the Bi-Se and Bi-Te Binary Systems

Thermodynamic descriptions of the Bi-Se and Bi-Te systems have been developed using the CALculation of PHAse Diagrams (CALPHAD) method based on the experimental data available in the literature. The liquid phases were described by the associated solution model for the Bi-Se and Bi-Te systems with Bi2Se3 and Bi2Te3 as associates, respectively. The intermetallics Bi2Se3, Bi3Se4, Bi8Se9, BiSe, Bi8Se7, Bi4Se3, Bi3Se2, Bi4Te5, Bi8Te9, BiTe, Bi4Te3, Bi2Te and Bi7Te3 were treated as stoichiometric compounds while Bi2Te3 was modeled by the sublattice model based on its homogeneity range and crystal structure. A set of self-consistent thermodynamic parameters for the Bi-Se and Bi-Te systems was obtained. Comparisons between the calculated results and experimental data available in the literature show that the most reliable experimental information can be satisfactorily accounted for by the present modeling.