No abstract

No abstract

No abstract

By using Differential Thermal Analysis (DTA) and Powder X-ray Diffraction (PXRD) techniques, the phase diagram of the MnTe-Sb2Te3 system has been constructed for the first time in the entire composition range. The system features two ternary layered van der Waals (vdW) compounds. Apart from known MnSb2Te4, novel MnSb4Te7 which a structural analogous of the known MnBi4Te7 was found in the system. Crystal structure parameters of both compounds were determined by Rietveld refinement using the fundamental parameter approach. Both compounds were found to decompose via peritectic reactions and possess significant homogeneity ranges. The title system is also characterized by the existence of the wide solid solution field based on the starting Sb2Te3. The present results would be useful for the bulk single crystal growth of both compounds from the liquid phase via the determination of primary crystallization areas.

Considering structural features of the already known tetradymite-like layered chalcogenide phases, we have attempt to synthesize a new mix-layered compound, SnBi 4 Te 4 . The newly synthesized alloy examined by means of differential thermal analysis, powder X-ray diffraction and scanning electron microscope techniques.The melting nature of the discovered phase is found to be incongruently at 831 K. The crystal structure of the SnBi 4 Te 4 was elucidated from powder pattern by Rietveld method. The determined crystal structure was found to derived from tetradymite type and featured by the alternation of theseven-layered (septuple) blocks of SnBi 2 Te 4 and bismuth bilayers. The result of this work, the existence of a new -SnBi 4 Te 4 compound in the Sn-Bi-Te ternary systemcan shed light for the incoming research works to search for similar phases in the other releated A IV -Bi-Te ( = , , ) systems.