Nov 10, 1994 - EUROPHYSICS LETTERS ... Due to charge transfer from boron to nitrogen, the buckled tubular structure forms .... me is the free-electron mass.
EUROPHYSICS LETTERS
10 November 1994
Europhys. Lett., 28 (51, pp. 335-340 (1994)
Stability and Band Gap Constancy of Boron Nitride Nanotubes. X. BLASE, A. RUBIO,S. G. LOUIEand M. L. COHEN Department of Physics, University of C a l q m i a at Berkeley Mahriak Sciences Division, Lawrence Berhky Laboratol=y - Bedwky, CA 94720, USA (received 6 June 1994; accepted 4 October 1994)
PACS. 7185T - Band structure of crystalline semiconductor compounds and insulators. PACS. 71.10 - General theories and computational techniques. PACS. 3680K - Electronic structure and spectra.
Abstract. - Extensive LDA and quasi-particle calculations have been performed on boron nitride (BN) single-wall and multi-wall nanotubes. Strain energies are found to be smaller for BN nanotubes than for carbon nanotubes of the same radius, owing to a buckling effect which stabilizes the BN tubular structure. For tubes larger than 9.5A in diameter, the lowest conduction band is predicted to be freeelectron-like with electronic charge density localized inside the tube. For these tubes, this band is at constant energy above the top of the valence band. Consequently, contrarily to carbon nanotubes, single- and multi-wall BN nanotubes are constant-band-gap materials, independent of their radius and helicity. In addition, we expect them to exhibit remarkable properties under n-type doping.
In a recent paper [l], the existence of boron nitride (BN) nanotubes was proposed. Based upon similarities between carbon and BN-based materials, it was suggested that these tubes may be stable and their electronic properties were studied within an empirical Tight-Binding (TB) approach. However, because of the lack of a total-energy calculation scheme within TB for BN-based materials, no evidence for the stability of BN nanotubes was given and the calculations were restricted to tubes with the
