Determination of chiral indices of individual single- and double-walled boron nitride nanotubes by electron diffraction

The intensities of electron diffraction patterns from individual (single-, double-walled) boron nitride nanotubes (BNNTs) as well as from bundles of these tubes have been recorded. The helicities have been systematically measured, and the diameter and the chiral indices have been determined. The analysis of 121 nanotubes reveals that 12% of the tubes are zigzag, while the distribution of the other helicities is uniform. The large value of the intertube distance and the significant difference of the chiral angle between the two constituent tubes in double-walled BNNTs indicate a lower interaction between the BN sheets than in bulk hexagonal BN. (c) 2006 American Institute of Physics.