The narrowest single-walled carbon nanotubes aligned in 1-nm sized channels of AlPO4-5 single crystals

We report the synthesis of the smallest single-wall carbon nanotubes (SWCNs), which are well aligned in the 1-nm-sized channels of AIPO(4)-5 single crystals. High-resolution transmission-electron microscope (HRTEM) observation showed that the SWCN is of a diameter 0.42 +/- 0.02 nm. We suspected that the SWCN has a roll-up vector (5,0) and is captured by a C-20 helmet. It is the smallest SWCN, which can be experimentally observed up to now. The fabrication of mono-sized and regular arrayed SWCNs is an important step towards understanding intrinsic fundamental physics and practical applications of the novel electronic system