A study was conducted, to show migration behavior of individual cesium ions inside and outside C60 fullerene cesium nanopeapods, observed in situ by transmission electron microscopy. It was also demonstrated that the behavior of doped Cs+ was significantly affected by elastic distortion and atomic defects in the C60 nanopeapods. Cesium-doped C60 nanopeapods, prepared from single-walled

carbon nanotubes were characterized by electron-energy-loss spectroscopy, to conduct the study. It was found that the doped Cs+ ions spread out homogeneously over the nanopeapod bundles Direct observation using high-resolution transmission electron microscopy showed the doping sites and dynamic behaviors of the doped Cs+ ions. It was found that Cs+ ions could be inserted into the spaces inside individual C660 nanopeapods and into the internanotube gaps in a bundle of these nanopeapods.

Site-Dependent Migration Behavior of Individual Cesium Ions inside and outside C60 Fullerene Nanopeapods. Sato, Y., Suenaga, K., Bandow, S., Iijima, S.: Small, 2008, 4[8], 1080-3