Home > Articles > Study of collective radial breathing-like modes in double-walled carbon nanotubes: Combination of continuous two-dimensional membrane theory and Raman spectroscopy
Resumen: Radial breathing modes (RBMs) are widely used for the atomic structure characterization and index assignment of single-walled carbon nanotubes (SWNTs) from resonant Raman spectroscopy. However, for double-walled carbon nanotubes (DWNTs), the use of conventional ¿RBM(d) formulas is complicated due to the van der Waals interaction between the layers, which strongly affects the frequencies of radial modes and leads to new collective vibrations. This paper presents an alternative way to theoretically study the collective radial breathing-like modes (RBLMs) of DWNTs and to account for interlayer interaction, namely the continuous two-dimensional membrane theory. We obtain an analytical ¿RBLM(do, di) relation, being the equivalent of the conventional ¿RBM(d) expressions, established for SWNTs. We compare our theoretical predictions with Raman data, measured on individual index-identified suspended DWNTs, and find a good agreement between experiment and theory. Moreover, we show that the interlayer coupling in individual DWNTs strongly depends on the interlayer distance, which is manifested in the frequency shifts of the RBLMs with respect to the RBMs of the individual inner and outer tubes. In terms of characterization, this means that the combination of Raman spectroscopy data and predictions of continuous membrane theory may give additional criteria for the index identification of DWNTs, namely the interlayer distance. Idioma: Inglés DOI: 10.1117/1.JNP.10.012502 Año: 2016 Publicado en: Journal of Nanophotonics 10, 1 (2016), 012502 [7 pp.] ISSN: 1934-2608 Factor impacto JCR: 1.325 (2016) Categ. JCR: OPTICS rank: 61 / 92 = 0.663 (2016) - Q3 - T3 Categ. JCR: NANOSCIENCE & NANOTECHNOLOGY rank: 72 / 87 = 0.828 (2016) - Q4 - T3 Factor impacto SCIMAGO: 0.518 - Condensed Matter Physics (Q2) - Nanoscience and Nanotechnology (Q2) - Electronic, Optical and Magnetic Materials (Q2)