Atom-Resolved Imaging of Carbon Hexagons of Carbon Nanotubes

Abstract

Atomic configurations of individual single-walled and double-walled carbon nanotubes have been obtained by high-resolution transmission electron microscopy with atomic sensitivity. A structural reconstruction is carried out by Fourier-filtered analysis of Moiré patterns, and it is now possible to acquire the carbon honeycomb lattice images through all of the periphery of individual nanotubes. This visualization technique provides supplementary access in nanoscale characterizations by combining with scanning tunneling microscopy.

Accurate determination of the chiral indices of individual carbon nanotubes by combining electron diffraction and Resonant Raman spectroscopy

“…At last, using the third method we can estimate n and m directly from the "intrinsic layer lines" by equations (5): ni = 22.862 ± 0.607 and mi = 11.431 ± 0.328; no = 28.159 ± 0.618 , mo =…”

“…So far, several approaches for the structure analysis of individual carbon nanotubes have been established. They are based on high-resolution transmission electron microscopy (HRTEM) [3][4][5][6], scanning tunneling microscopy [7][8][9], electron diffraction (ED) [10][11][12][13][14][15][16][17], photoluminescence (PL) [18], Rayleigh spectroscopy [19][20][21], optical absorption [22], and resonant Raman spectroscopy (RRS) [23][24][25][26][27][28].…”

The Identification of Inner Tube Defects in Double‐Wall Carbon Nanotubes

“…Evidence of correlation in the atomic positions in DWCNTs has been observed using both conventional TEM,20, 21 aberration corrected (AC‐) high resolution (HR‐)22, 23 and scanning (S‐) TEM 24. However, conventional HRTEM does not resolve the atomic positions in the carbon lattice and any correlation between the structures in the inner and outer tubes must be indirectly inferred from coincidence of the lattice fringes20 and subsequent comparison with simulations 21.…”

“…Using AC‐HRTEM it is possible to obtain atomic resolution images, although detailed determination of the structure of a DWCNT is complicated due to the complex moiré pattern resulting from contributions to the image from both tubes. However by careful comparison of experimental images with simulations the structure of DWCNTs has been determined from AC‐HRTEM images 22, 23…”

“…Consequently, without the ability to separate structural information from the two tubes, relative atomic positions cannot be determined and the identification of defects is limited to those in the outer tube. Fourier filtering of AC‐HRTEM images can be used to obtain information from only the top or bottom wall of a SWCNT,23 which enables topological defects to be located and studied without the interference of information from neighbouring walls 26…”