Wall-to-wall stress induced in (6,5) semiconducting nanotubes by encapsulation in metallic outer tubes of different diameters: A resonance Raman study of individual C60-derived double-wall carbon nanotubes

Abstract

We measure resonant Raman scattering from 11 individual C 60 -derived double wall carbon nanotubes with inner semiconducting (6,5) tubes and outer metallic tubes. The Raman spectra show the radial breathing mode (RBM) of the inner and the outer tubes simultaneously in resonance with the same laser energy. We observe that an increase in the RBM frequency of the inner tubes is related to an increase in the RBM frequency of the outer tubes. The Raman spectra also contain a sharp G − feature that increases in frequency as the nominal diameter of the outer metallic tubes decreases. Finally, the one phonon second-order D band mode shows a two way frequency splitting that decreases with decreasing nominal wall to wall distances. We suggest that the stress which increases with decreasing nominal WtW distances is responsible for the observed hardening of the frequencies of the RBM, D an G − modes of the inner (6,5) semiconducting tubes.

Study of Carbon Nanotube-Substrate Interaction

“…Villalpando-Paez et al [61] showed that the (6,5) inner tubes in a double-wall carbon nanotube (DWNT) show different behavior when surrounded by different (n, m) outer tubes. The extra effect of a substrate in this case is a broad and open issue for future research.…”

Intrinsic phonon properties of double-walled carbon nanotubes

“…In figure 6 we plot together the frequencies of the TO G-mode of the inner tube measured on index-identified DWNT (blue symbols) and, on the other hand, the ones obtained on (6,5)@ SC DWNTs by Villalpando-Paez et al (red symbols) [19].…”

“…It must be emphasized that the index-assignment of the outer tubes of these later DWNTs, and then their δr values, was reexamined by comparing the experimental RBLMs of reference [19] with the results of the model presented in the previous subsection of this paper. A shift of the TO mode is observed in a large interlayer distance range.…”

Экспериментальное Исследование Динамики Решетки Индивидуальных Полупроводниковых Двустенных Углеродных Нанотрубок: Тангенциальные G-Моды

“…Хотя ранее и было проведено изучение индиви-дуальных полупроводниковых ДУНТ расположенных на подложке [11][12][13], в этих работах структуру двустенных нанотрубок идентифицировали косвенным способом с 328…”

“…Хотя ранее и было проведено изучение индиви-дуальных полупроводниковых ДУНТ расположенных на подложке [11][12][13] (27,17). Спектры нормализованы по интенсивности G-моды для иллюстративных целей.…”