Rhenium-Catalyzed Growth Carbon Nanotubes

Using a modified "fixed-bed" chemical vapor deposition method, diamagnetic single-, double-, and multiwalled carbon nanotubes were synthesized. For the first time, we show that rhenium is a suitable catalyst for the synthesis of such diamagnetic nanotubes with uniform diameter and a defined numbers of shells. Scanning and transmission electron microscopy investigations, Raman spectroscopy, and magnetic measurements show the tubular structure, the high crystallinity, and the diamagnetic character of the grown nanotubes. We compare the growth mechanism of the Re-catalyzed nanotubes with the growth behavior supported by the conventional catalyst metals ferromagnetic iron, cobalt, and nickel.