Ab initiocalculations of the lattice dynamics of boron nitride nanotubes
Open Access
- 30 July 2003
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 68 (4), 045425
- https://doi.org/10.1103/physrevb.68.045425
Abstract
We present an extensive first-principles study of the phonons in boron nitride nanotubes using density functional perturbation theory in the local density approximation. Based on the nonsymmorphic rod-group symmetry of the tubes, the Raman- and infrared-active modes at the point of the one-dimensional Brillouin zone are evaluated. For zigzag and chiral nanotubes, the set of infrared-active modes is a subset of the Raman-active modes. In particular, the radial breathing mode is not only Raman but also infrared active. However, for armchair tubes, the sets of infrared- and Raman-active modes are disjoint. This may serve to spectroscopically distinguish between macroscopic samples of zigzag-chiral and armchair nanotubes. We present the frequencies of the active modes of zigzag, chiral, and armchair tubes as a function of the tube diameter and compare the results with the frequencies obtained by the zone-folding method, i.e., the rolling of a single hexagonal BN sheet into a tube. Except for the high-frequency tangential modes, the zone-folding results are in very good agreement with the ab initio calculations. The radial breathing mode frequency can be derived by folding a sheet of finite width. Finally, we show that the effects of bundling on the phonon frequencies are small. This demonstrates that the obtained results for isolated BN tubes may serve as a basis for an accurate assignment of phonon modes in spectroscopic measurements.
Keywords
This publication has 52 references indexed in Scilit:
- Long ropes of boron nitride nanotubes grown by a continuous laser heatingApplied Physics Letters, 2000
- Mass-production of boron nitride double-wall nanotubes and nanococoonsChemical Physics Letters, 2000
- Single-walled B-doped carbon, B/N-doped carbon and BN nanotubes synthesized from single-walled carbon nanotubes through a substitution reactionChemical Physics Letters, 1999
- Synthesis of boron nitride nanotubes at low temperatures using reactive ball millingChemical Physics Letters, 1999
- Synthesis of boron nitride nanotubes by means of excimer laser ablation at high temperatureApplied Physics Letters, 1998
- Boron Nitride Nanotubes with Reduced Numbers of Layers Synthesized by Arc DischargePhysical Review Letters, 1996
- Boron Nitride NanotubesScience, 1995
- Stability and Band Gap Constancy of Boron Nitride NanotubesEurophysics Letters, 1994
- Theory of graphitic boron nitride nanotubesPhysical Review B, 1994
- Helical microtubules of graphitic carbonNature, 1991