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.

本研究旨在探明Tl-Pb-Bi-Tb-Te体系中Tl₄PbTe₃-Tl₉TbTe₆-Tl₉BiTe₆截面的相平衡关系。本研究采用差热分析、粉末X射线衍射法及显微硬度测试等多种物理化学分析方法，绘制了Tl₄PbTe₃-Tl₉TbTe₆边界体系的相图、若干等截面图、液相面与固相面投影图，以及840 K和860 K下的等温截面图。本体系中发现了具有Tl₅Te₃结构的无限固溶体（δ相），该类固溶体作为热电材料具备重要研究价值。