Weak Response of Metallic Single-Walled Carbon Nanotubes to C-60 Encapsulation Studied by Resonance Raman Spectroscopy

作者：Joung Soon Kil; Okazaki Toshiya^*; Okada Susumu; Iijima Sumio

来源：Journal of Physical Chemistry C, 2012, 116(44): 23844-23850.

DOI：10.1021/jp309379r

Metallic single-walled carbon nanotubes (SWCNTs) have been regarded as unique quasi-1D metallic systems. Their basic properties significantly differ from those of their semiconducting counterparts even though their chemical compositions and sizes are nearly identical to each other. In this study, we investigate the effects of C-60 fullerene encapsulation on the phonon and electronic properties of metallic SWCNTs by resonance Raman spectroscopy. The changes in the radial breathing mode frequencies and the optical transition energies after C-60 insertions show characteristic tube diameter dependences, as in the case of the corresponding semiconducting SWCNTs. Although the observed behaviors can be attributed to the intermolecular interaction between SWCNTs and the encapsulated C-60, similar to the corresponding semiconducting SWCNTs, the strength of the interaction is measurably weaker than that of semiconducting SWCNTs. The present findings provide important insight into the essential differences in the basic nature of metallic and semiconducting SWCNTs.

• 出版日期2012-11-8