Phase equilibria and decomposition of solid solutions in the YbTe–SnTe–PbTe system

Resumo

Phase equilibria in the YbTe–SnTe–PbTe system have been studied using differential thermal analysis, X-ray diffraction, scanning electron microscopy, and emf measurements on YbTe concentration cells. We have mapped out a number of vertical sections, the 400-K isothermal section of the YbTe–SnTe–PbTe phase diagram, and projections of its liquidus and solidus surfaces. The results demonstrate that the system is characterized by the formation of a continuous series of high-temperature solid solutions with a cubic structure (NaCl type), which undergo decomposition below ~1050 K. At room temperature, the YbTe solubility in the Sn_1–xPb_xTe solid solution system is ~33–35 mol %, whereas the extent of the YbTe-based solid solution series does not exceed 3 mol %.