Electron nano-diffraction study of carbon single-walled nanotube ropes

Electron diffraction patterns from regions about 0.7 nm in diameter have been obtained, in conjunction with dark-field imaging, in a scanning transmission electron microscope to study the average helicity and the local variations of helicity of the individual carbon nanotubes within the ropes of single-walled carbon nanotubes recently produced by double laser irradiation. It has been found that the predominant helicity is that predicted theoretically, namely that giving the metallic, C-5v symmetry, (10,10) tube.