Experimental Study of the Tl4PbTe3-Tl9TbTe6-Tl9BiTe6 Section of the Tl-Pb-Bi-Tb-Te System

The aim of the present study was to determine the phase relations in the Tl4PbTe3-Tl9TbTe6-Tl9BiTe6 section of the Tl-Pb-Bi-Tb-Te system. Based on a set of the methods of the physicochemical analysis (differential thermal analysis, powder X-ray diffraction method as well as microhardness measurements), the phase diagram of the Tl4PbTe3-Tl9TbTe6 boundary system, some isopleth sections, liquidus and solidus surfaces projections, as well as isothermal sections at 840 and 860 K, were plotted. Unlimited solid solutions with the Tl5Te3 structure (δ-phase) were found in the system, which are of interest as a thermoelectric materials.