ZA-derived phonons in the Raman spectra of single-walled carbon nanotubes

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Details zur Publikation

Autorinnen und Autoren: Vierck A, Gannott F, Schweiger M, Zaumseil J, Maultzsch J
Zeitschrift: Carbon
Verlag: PERGAMON-ELSEVIER SCIENCE LTD
Jahr der Veröffentlichung: 2017
Band: 117
Seitenbereich: 360-366
ISSN: 0008-6223


Abstract


We report the observation of four Raman modes in individual, aligned single-walled carbon nanotubes, with frequencies between the RBM and D modes, and above the G(+/-) modes. By studying the diameter and excitation-energy dependence, we find that these strongly dispersive and comparatively intense modes share the lowest-frequency helical phonon branch as the origin, which can be derived from the out-of plane acoustic (ZA) phonon branch of graphene. This ZA phonon is observed due to a defect-assisted, double-resonant process, similar to the D mode; its two-phonon overtones and combinations with transverse optical (TO) phonons do not require defects. Our assignment is supported by a theoretical model based on sixth-nearest neighbour tight-binding and a force-constant approach. We present a complete theoretical evaluation of the diameter and excitation-energy dependence of the ZA, 2ZA, and TO +/- ZA modes, which fits very well to our experimental results and previous studies of the so-called region of intermediate frequency modes. (C) 2017 Elsevier Ltd. All rights reserved.



FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Gannott, Florentina Dr.-Ing.
Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe)
Maultzsch, Janina Prof. Dr.
Lehrstuhl für Experimentalphysik
Schweiger, Manuel
Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe)


Einrichtungen weiterer Autorinnen und Autoren

Ruprecht-Karls-Universität Heidelberg
Technische Universität Berlin


Zitierweisen

APA:
Vierck, A., Gannott, F., Schweiger, M., Zaumseil, J., & Maultzsch, J. (2017). ZA-derived phonons in the Raman spectra of single-walled carbon nanotubes. Carbon, 117, 360-366. https://dx.doi.org/10.1016/j.carbon.2017.02.101

MLA:
Vierck, Asmus, et al. "ZA-derived phonons in the Raman spectra of single-walled carbon nanotubes." Carbon 117 (2017): 360-366.

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