Morphology-Tuned Synthesis of Single-Crystalline V5Si3 Nanotubes and Nanowires

We report the morphology-tuned synthesis of single-crystal line V5Si3 nanotubes and nanowires. Free-standing hexagonal V5Si3 nanostructures are grown on a vanadium foil substrate placed on Si powder by a chemical vapor deposition method. By controlling the reaction time and substrate temperature, we have succeeded in morphology tuning Of V5Si3 nanotubes and nanowires. When the downstream temperature is fixed at 950 degrees C, V5Si3 nanotubes are formed with the reaction time of 5 min and V5Si3 nanowires are obtained with the reaction time of 15 min. With the downstream temperature of 950 degrees C and the reaction time of 15 min, when Si powder is mixed with carbon powder to the Si composition of 10-50%, both nanotubes and nanowires are simultaneously formed on the vanadium foil along the temperature gradient. Single-crystalline V5Si3 nanotubes thus synthesized are the first metal silicide nanotubes reported so far.