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

Vierck A, Gannott F, Schweiger M, Zaumseil J, Maultzsch J (2017)

Publication Status: Published

Publication Type: Journal article

Publication year: 2017

Journal

Carbon Elsevier

Publisher: PERGAMON-ELSEVIER SCIENCE LTD

Book Volume: 117

Pages Range: 360-366

DOI: 10.1016/j.carbon.2017.02.101

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.

Authors with CRIS profile

Florentina Gannott Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe) (LSP) Manuel Schweiger Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe) (LSP) Janina Maultzsch Lehrstuhl für Experimentalphysik

Involved external institutions

Technische Universität Berlin DE Germany (DE) Ruprecht-Karls-Universität Heidelberg DE Germany (DE)

How to cite

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://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.

BibTeX: Download