The tellurides of bismuth and antimony (Bi 2 Te 3 and Sb 2 Te 3 ) are prominent members of the V 2 VI 3 material family that exhibit promising topological properties. We provide a method for the rational synthesis of mixed crystals of these materials ((Bi x Sb 1−x ) 2 Te 3 with x = 0.1, ..., 0.9) by means of a bottom-up chemical vapor transport (CVT) approach. Thermodynamic calculations showed the synthesis to be possible in the temperature range of 390−560 °C without significant enrichment of either component and without adding a transport agent. The starting materials were synthesized and verified by X-ray diffraction (XRD). Optimization experiments showed the ideal conditions for nanosheet synthesis to be T 2 = 560 °C, T 1 = 390 °C with a reaction time of t = 36 h. Crystals with heights of down to 12 nm (12 quintuple layers) were synthesized and analyzed by means of scanning electron microscopy, energy-dispersive X-ray spectrometry, and atomic force microscopy. High-resolution transmission electron microscopy confirmed the R3̅ m crystal structure, high crystallinity, and overall quality of the synthesized (Bi x Sb 1−x ) 2 Te 3 nanosheets. Magnetotransport measurements revealed that such ternary compounds can have a significantly reduced carrier density compared to the binary parent compounds.