Experimental Study of the Tl 4 PbTe 3 -Tl 9 TbTe 6 -Tl 9 BiTe 6 Section of the Tl-Pb-Bi-Tb-Te System

摘要

The aim of the present study was to determine the phase relations in the Tl 4 PbTe 3 -Tl 9 TbTe 6 -Tl 9 BiTe 6 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 Tl 4 PbTe 3 -Tl 9 TbTe 6 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 Tl 5 Te 3 structure (δ-phase) were found in the system, which are of interest as a thermoelectric materials.