Study of the packing of double-walled carbon nanotubes into bundles by transmission electron microscopy and electron diffraction

The structure of bundles of double-walled carbon nanotubes synthesized by catalytic chemical vapour deposition is investigated using transmission electron microscopy and electron diffraction. Small and well-crystallized bundles are observed and characterized by transmission electron microscopy and electron diffraction and display particular features that reveal unambiguously the presence of double-walled nanotubes constituting the bundles. Other remarkable results are obtained focusing our interest on the rings of double-walled nanotube bundles. The experimental results are analysed with the help of the kinematical theory of diffraction. We conclude this study by the discussion of the growth mechanism of these bundles.