Experimental examination and thermodynamic description of the ternary Bi-Ge-Ga,Zn systems

Abstract

Due to the wide application of systems based on germanium ternary Bi-Ga-Ge and Bi-Ge-Zn systems were experimentally tested in this study. Used experimental techniques were scanning electron microscope with energy dispersive spectroscopy (SEM-EDS), x-ray diffraction (XRD) and differential thermal analysis (DTA). Three groups of samples were prepared and tested. Alloys were from two isothermal sections at 100 and 300 °C and three vertical sections. Obtained results of experimental tests were compared with predicted phase diagrams. Comparison of EDS and DTA results with calculated phase diagrams of the ternary Bi-Ga-Ge system results in good agreement. While for Bi-Ge-Zn was necessary to introduce new ternary parameters. Introduced ternary parameters were based on experimental results from this study. The thermodynamic descriptions of the ternary Bi-Ga-Ge and Bi-Ge-Zn systems have been developed by using CALPHAD method. Reasonable agreement between experimental data and the calculated phase diagrams has been reached for both ternary Bi-Ga-Ge and Bi-Ge-Zn systems. The liquid projection and invariant equilibria have been calculated by using obtained thermodynamic parameters.