Work

Electronic properties of Cs-intercalated single-walled carbon nanotubes derived from nuclear magnetic resonance

Year: 2011

Type: article

Abstract: We report on the electronic properties of Cs-intercalated single-walled carbon nanotubes (SWNTs). A detailed analysis of the 13 C and 133 Cs nuclear magnetic resonance (NMR) spectra reveals an increased metallization of the pristine SWNTs under Cs intercalation. The 'metallization' of Cs x C materials where x =0–0.144 is evidenced from the increased local electronic density of states (DOS) n ( E F ) at the Fermi level of the SWNTs as determined from spin–lattice relaxation measurements. In particular, there are two distinct electronic phases called α and β and the transition between these occurs around x =0.05. The electronic DOS at the Fermi level increases monotonically at low intercalation levels x <0.05 (α-phase), whereas it reaches a plateau in the range 0.05⩽ x ⩽0.143 at high intercalation levels (β-phase). The new β-phase is accompanied by a hybridization of Cs(6s) orbitals with C(sp 2 ) orbitals of the SWNTs. In both phases, two types of metallic nanotubes are found with a low and a high local n ( E F ), corresponding to different local electronic band structures of the SWNTs.

Source: New Journal of Physics

DOI: 10.1088/1367-2630/13/5/053045