2020-04-05 17:29:32

The mass small radius tubules

责任者: YORIKAWA, H;MURAMATSU, S 单位: 来源出处: PHYSICAL REVIEW B, v 52, JUL 15 1995, p 2723- 2727 摘要: The effect of the mixing between pi and sigma orbitals upon the energy gaps (E(g)s) of semiconducting carbon nanotubules has been theoretically studied within the tight-binding approximation. The magnitude of a chirality-dependent energy gap (E(theta)) has been estimated. This term cannot be neglected for tubules with a small radius. The relation of E(g) to R, E(g) proportional to R(-1), no longer holds for small-radius tubules. An approximate expression for E(g), which can be applicable even to small-radius semiconducting tubules, is presented. In addition, it is shown that the E(theta) is well correlated with a fraction of the sigma component in the wave functions for the conduction-band bottom and valence-band top. 关键词: COALESCENCE; DIRECT LASER VAPORIZATION; FULLERENE; MASS DISTRIBUTION; TOF MASS SPECTROMETRY TOF MASS SPECTROMETRY; CARBON NANOTUBES; MICROTUBULES; GROWTH