Abstract
Various Pb-Sb-Se alloys are promising topological insulators and thermoelectric materials. Phase diagrams of the Pb-Sb-Se ternary system are thus fundamentally important. The liquidus projection of the Pb-Sb-Se ternary system and the isoplethal section of PbSe-Sb2Se3 are determined in this study. Various Pb-Sb-Se alloys are prepared, and their primary solidification phases are determined. There are eight primary solidification phases: Pb, Sb, Se, PbSe, Sb2Se3, PbSb2Se4, Pb2Sb6Se11 and Pb2Sb9Se9.; moreover, there are two miscibility gaps. The reaction temperatures of the PbSe-Se2Sb3 isoplethal section and temperature descending directions of the univariant lines in the Pb-Sb-Se liquidus projection are determined based on thermal analysis results and requirement of mass balance. There are eight ternary invariant reactions in the Pb-Sb-Se ternary system, and that of the lowest reaction temperature is L=PbSe+ Pb +Se at 250±2oC.