Dumbbell-like BiTe nanowires with segmentally tailored composition and dimension were synthesized by galvanic displacement reaction of multi-segmented NiFe nanowires with Ni-rich and Fe-rich segments. The composition and dimension of each segment were determined by the tuned sacrificial segments to control the galvanic displacement reaction rate. The composition and dimension of each segment were determined by the tuned sacrificial segments to control the galvanic displacement reaction rate. For examples, the bismuth content in BixTe1-x adjusted from 32 to 60 at.% by controlling the Fe content in NiFe sacrificial nanowires. The ability to tune the dimension of segments was demonstrated by the diameter variation from 99 to 551 nm with the segment length from 97 nm to 1 mu m. (C) 2012 Elsevier Ltd. All rights reserved.