Experimental study of the phase diagram and thermodynamic properties of the Tl-Sb-S system

Abstract Phase equilibria in the ternary Tl-Sb-S system have been experimentally re-investigated over the entire composition range by means of powder X-ray diffraction (PXRD), differential thermal analysis (DTA) and electro-motive force measurements (EMF) applied to equilibrated alloys. Four vertical sections and isothermal section at 300 K as well as the liquidus surface projection were constructed based on the experimental data. The homogeneity ranges and primary crystallization fields of all phases as well as the types and temperatures of non- and monovariant equilibria were determined. The existence of the earlier reported ternary TlSb 5 S 8 , TlSb 3 S 5 , TlSbS 3 , TlSbS 2 , Tl 3 SbS 4 and Tl 3 SbS 3 compounds were confirmed, whereas the two compounds, Tl 2 SbS 2 and Tl 4 SbS 2 were not found during the present investigation. The standard formation thermodynamic functions and standard entropies of the confirmed compounds were calculated based on EMF measurements data.