R. Ciardi

Carbon nanotubes and nanowires grown from spherical carbon nano-particles

Abstract In this Letter, we report a new method for the fabrication of carbon nanotubes (CNT) and nanowires where amorphous hydrogenated carbon nano-particles were used as precursor, without metal catalyst addition. In particular, depending on the process parameters, we obtained single walled nanotubes (SWNTs) with mean diameter 1.2 nm and carbon nanowires with mean diameter 250 nm. A discussion on the possible growth mechanism is also reported.

Self-assembled carbon nanotubes grown without catalyst from nanosized carbon particles adsorbed on silicon

Carbon nanotubes films have been prepared by low-velocity spraying of carbon nanosized particles on heated Si substrate. Studies reveal that by properly choosing the deposition temperature, well-aligned carbon nanotubes are self-assembled from the particles without a catalyst. Raman scattering and reflection high-energy electron diffraction show that the tubes are bundles of single-wall nanotubes.

Second- and third- harmonic generation in single-walled carbon nanotubes at nanosecond time scale

Second- and third-harmonic generation in single-walled carbon nanotube films is experimentally investigated with the fundamental 1064nm radiation from a Q-switched Nd:YAG laser. Measurements were performed both on commercially available carbon nanotubes and on samples of carbon nanotubes grown with a catalyst-free method. Third-harmonic generation was observed in both samples while only the sample grown with a catalyst-free method generated a second-harmonic signal. The quantum yield of second- and third-harmonic signal was proven to scale, respectively, with the second and third power of the pump pulse energy up to intensities of 109W∕cm2.