Atomic-resolution imaging of the nucleation points of single-walled carbon nanotubes

The determination of the atomic structures of nucleation points for SWNTs and the analysis of the effects of SWNT-catalyst interactions on SWNT growth, was investigated. The atomic information in the nucleation points of SWNTs was obtained through a rational substrate preparation approach and atomic-resolution transmission electron microscopy. Catalytic cobalt nanoparticles were directly synthesized on SiO2 nanoballs located on a TEM copper grid. 50 mm thick SiO2 nanoballs were deposited on the carbon-film covered copper grid, and a 30 mm thick SiO2 film was sputtered on them using a conventional vacuum evaporator. Thermal annealing converted the Co thin film to metal nanoparticles. The observed growth pathway of SWNTs demonstrated that the relevant step sites were generated during the CVD reaction. The future aspects involve performing an in situ dynamic study of SWNT growth under more realistic conditions using environmental TEM.