Structure and chirality distribution of multiwalled boron nitride nanotubes

We report on a high-resolution electron diffraction study of the structure of individual multiwalled boron nitride nanotubes (MW-BNNTs). The tube chirality was determined by electron diffraction. Diffraction patterns were recorded from small sections of the nanotubes, ~125 nm long, using the nanoarea electron diffraction technique. Accurate measurements of the MW-BNNT chiral angles and their distribution were made from diffraction patterns. Generally, the tube chiralities within each MW-BNNT are strongly correlated; clustering around a single chirality with a dispersion of a few degrees. Multihelix nanotubes were rarely observed. Statistics based on 67 nanotubes revealed a dispersion of the chiral angles (α) with some preference of tubes in the ranges of 10°≤α≤15° and 25°≤α≤30°. Since various properties of nanotubes depend on the tube structure (diameter and chirality), the results presented here have general significances to nanotube growth and applications.