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

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 850 K, 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 850 K.