Synthesis and structural characterization of alkali-metal intercalated single-walled carbon nanotubes

In order to investigate the mechanism of alkali-metal insertion into single-walled carbon nanotubes (SWCNTs), Raman and XRD measurements of several alkali-metals (Li, K) and open-end, closed-end SWCNTs compounds have been performed. By doping alkali-metal into the open-end SWCNTs, firstly the Raman G-band shifts towards the higher energy side due to the stress induced by the alkali-metal insertion between the tubes, and then shows a downshift mainly caused by the effect of the charge transfer from the alkali-metals inserted inside the tubes, which leads to fewer structural fluctuations than the metals between the tubes.