The Cs intercalation process in multi-walled C nanotubes was studied by means of cross-sectional scanning photo-emission microscopy. The Cs atoms initially deposited on the tips of aligned nanotubes diffused toward their roots. The Cs diffusion constant for the multi-walled nanotubes at room temperature was deduced from the Cs distribution measured along the axes of the tubes. A value of 2 x 10–12cm2/s was obtained, which was 7 orders of magnitude smaller than that in graphite; although the local atomic structure of an intercalated multi-walled nanotube was very similar to that of intercalated graphite.

Extremely Small Diffusion Constant of Cs in Multiwalled Carbon Nanotubes. S.Suzuki, Y.Watanabe, T.Ogino, S.Heun, L.Gregoratti, A.Barinov, B.Kaulich, M.Kiskinova, W.Zhu, C.Bower, O.Zhou: Journal of Applied Physics, 2002, 92[12], 7527-31