Phase diagram of the YbTe–Sb2Te3–Bi2Te3 quasi-ternary system

Abstract

The phase equilibria in the YbTe–Sb2Te3–Bi2Te3 quasi-ternary system were investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscope with energy dispersive analysis (SEM-EDS) techniques. Two isothermal sections of the system at 300 and 850K, the projection of the liquidus surface as well as several isopleth sections were experimentally carried out. The boundary quasi-binary sections YbTe–Bi2Te3 and YbTe–Sb2Te3 restudied and existence of the four ternary compounds YbSb2Te4, YbSb4Te7, YbBi2Te4 and YbBi4Te7 reported earlier were not confirmed. Along the boundary Sb2Te3–Bi2Te3 system the existence of continuous solid solubility field with the tetradymite type crystal structure was revealed at 300 and 850K.