Abstract
We report on electron energy-loss spectroscopy studies of the electronic properties of multiwall boron nitride nanotubes, in terms of the and excitation edges and of the q-dependent energy-loss function. The q-dependent dielectric function shows a strong dispersion in momentum of the π and plasmons indicating that they are spatially delocalized along the tube axis as expected according to their characteristic two-dimensional graphiticlike structure, and nondispersing excitations at 11 and 12 eV. The dielectric function ɛ of the boron nitride nanotubes reveals an intense interband transition at 5.4 eV, which is shifted to lower energies by 0.6 eV when compared to hexagonal BN in good agreement with recent theoretical band-structure calculations of boron nitride nanotubes.
- Received 3 September 2002
DOI:https://doi.org/10.1103/PhysRevB.67.035429
©2003 American Physical Society