Atomic Step-Templated Formation of Single-Wall Carbon Nanotube Patterns

\textbf{Single-wall carbon nanotubes catalytically produced on miscut C-plane sapphire wafers grow along the 0.2nm-high atomic steps of the vicinal $\alpha ${\-}Al}$_{2}$\textbf{O}$_{3}$\textbf{ (0001)~surfaces, yielding highly aligned, dense arrays of discrete nanotubes on a dielectric material [1]. The nanotubes reproduce the atomic features of the surface, including steps, facets and kinks. Microscopy, X-ray diffraction and single-nanotube Raman spectroscopy [2] shed light into the possible structure and mechanism of the step-templated carbon nanotube growth. The orientation, density and morphology of the atomic steps can be macroscopically controlled by the crystal cutting process. Hence, these findings open up the possibility of assembling nanotube architectures by atomic-scale surface engineering.} [1] A. Ismach, et al.,\textit{ Angew. Chem. Int. Ed.} \textbf{2004}, 43, 6140. [2] M. Souza, et al., \textit{Phys. Rev. B} \textbf{2004}, 241403R.