A newly refined version of the phase diagram of the PbTe–Bi2Te3 pseudo-binary system was construc-ted using differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. It was established that the system forms three tetradymite-type layered ternary compounds, namely PbBi2Te4, PbBi4Te7, and PbBi6Te10, and all these phases melt with peritectic decomposition. However, earlier reported Pb3Bi4Te9, Pb2Bi6Te11, and PbBi8Te13 compounds were not confirmed in our XRD studies. The existence of homogeneity areas based on all ternary compounds and the starting phases PbTe and Bi2Te3 was detected. The crystal structure of the ternary compounds was solved by Rietveld refinement. The newly constructed phase diagram provides very valuable information for choosing appropriate conditions for the synthesis of bulk samples or single crystals growth

For the SnTe–PbTe–Bi2Te3 system, an analytical model of the temperature-composition dependencies of the crystallization surfaces of the SnTe, PbTe, Bi2Te3, compounds and the ternary PB(Sn)Bi2Te4, Pb(Sn)Bi4Te7, PB(Sn)Bi6Te10 phases formed on based on them was developed and visualized using the 3D analytical function of OriginLab software. The analytical multi-3D model of the phase diagram of the SnTe–PbTe–Bi2Te3 system allows drawing a three-dimensional image of the phases in equilibrium from different angles, obtaining 2D projections, and tabulating the coordinates of the phase diagram. These coordinates as form of matrices – 100x100 = 10.000 and 50x50 = 2500 tabular data create chance for selecting optimal composition and temperature values for the synthesis of alloys, and crystal growth