Influence of surface structure modifications on the growth of carbon-nanotubes on the SiC) surfaces

We report experimental results of carbon nanotubes (CNTs) formation on SiC ( 0 0 0 1 ¯ ) surfaces by scanning tunneling microscopy (STM) and transmission electron microscopy (TEM). The CNTs were formed densely and uniformly after annealing a SiC ( 0 0 0 1 ¯ ) surface at 1700 °C in a low vacuum. However, the CNTs were not formed after annealing the SiC ( 0 0 0 1 ¯ ) surface at 1050 °C in an ultra-high vacuum followed by annealing the surface at 1700 °C in the low vacuum. From the STM and TEM observations, we found that the graphite layers without defects obstruct the formation of the precursor of CNTs on the SiC ( 0 0 0 1 ¯ ) surface.