Carbon nanotube growth at the tip of SiO2 nanocone

A well aligned growth of carbon nanotube (CNT) at the tip of SiO2 nanocone using chemical vapor deposition (CVD) method is described. Fe particle at the tip of a nanocone has been observed to work as the catalyst for CNT growth. Initially, a number of self organized SiO2 nanocones were grown via thermal annealing of MnCl2 on Si substrate in the presence of H2 gas. The average diameters of the tip and base of the nanocones were nearly 50 nm and 1 μm, respectively, with length up to 2.4 μm. At the tip of the nanocone a CNT was grown successfully. The CNT grows from the tip of the nanocone where Fe particles accumulate after the reduction of FeCl3 at 950 °C. The accumulation point of Fe particles depends on the orientation of the nanocone tip inside the reaction tube during CVD process. Therefore, the alignment of nanotube at the tip of SiO2 nanocone can be controlled by orientation of the nanocone in the reaction tube.