The study of Cs intercalation process in multiwalled carbon nanotubes was done by cross-sectional scanning photoemission microscopy. It was found that Cs atoms initially deposited on the tips of aligned nanotubes diffused towards their roots. The evaluation of Cs diffusion constant for the multiwalled carbon nanotubes at room temperature was based upon the Cs distribution measured along the axes of the tubes.

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