The origin of grown-in defects in carbon nanotubes was elucidated by in situ atomic-scale environmental transmission electron microscopic observations of the chemical vapor deposition growth of carbon nanotubes. The high-resolution environmental transmission electron microscope observations clearly demonstrated that the deformation of nanoparticle catalysts during the growth of carbon nanotubes triggered the formation of various defects in carbon nanotubes. The small deformation of nanoparticle catalysts at the interface with carbon nanotubes gave rise to the formation of bends and to disorder of the interlayer spacing in carbon nanotubes. The changes in the diameter and number of graphitic layers in carbon nanotubes were caused by the large protrusion on and shrink deformations of nanoparticle catalysts. This study provided insight into strategies for controlling the grown-in defects of carbon nanotubes.

Elucidation of the Origin of Grown-In Defects in Carbon Nanotubes. H.Yoshida, S.Takeda: Carbon, 2014, 70, 266-72