Different Approach to Thermodynamic Description of Bi-Te Binary System

The aim this work was the reinvestigation of phase equilibria in Bi-Te system. The as-cast and long-time equilibrated alloys of Bi-Te binary system were analysed by scanning electron microscopy, X-ray diffraction (XRD) and differential thermal analysis (DTA) methods. The primary solidified phases were identified for as-cast samples. The existence of the four intermetallic phases: Bi2Te3, BiTe, Bi2Te, Bi7Te3 was confirmed. Three of them melt incongruently in peritectic reactions. The model parameters of all phases in this system were assessed by optimization using available data by Calphad method. The stabilisation of these phases in other ternary systems was discussed taking into consideration its future application in thermodynamic description of Ag-Bi-Te ternary system.

Automated summary

The aim of this work was to reinvestigate phase equilibria in the Bi-Te system. As-cast and long-time equilibrated alloys were analyzed using scanning electron microscopy, X-ray diffraction (XRD), and differential thermal analysis (DTA). The primary solidified phases were identified in as-cast samples, including four intermetallic phases: Bi2Te3, BiTe, Bi2Te, and Bi7Te3. Optimization of model parameters for all phases in this system was performed using the Calphad method. The stability of these phases in other ternary systems and their potential application in the thermodynamic description of the Ag-Bi-Te ternary system were discussed.