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Title: Origin of a Raman scattering peak generated in single-walled carbon nanotubes by X-ray irradiation and subsequent thermal annealing

Abstract

We have found that a Raman scattering (RS) peak around 1870 cm{sup −1} was produced by the annealing of the X-ray irradiated film of single-walled carbon nanotubes (SWNTs) at 450 {sup o}C. The intensity of 1870-cm{sup −1} peak showed a maximum at the probe energy of 2.3 eV for the RS spectroscopy with various probe lasers. Both the peak position and the probe-energy dependence were almost identical to those of the one-dimensional carbon chains previously reported in multi-walled carbon nanotubes. Consequently, we concluded that the 1870-cm{sup −1} peak found in the present study is attributed to carbon chains. The formation of carbon chains by the annealing at temperature lower than 500 {sup o}C is firstly reported by the present study. The carbon chains would be formed by aggregation of the interstitial carbons, which are formed as a counterpart of carbon vacancies by X-ray irradiation diffused on SWNT walls. The result indicates that the combination of X-ray irradiation and subsequent thermal annealing is a feasible tool for generating new nanostructures in SWNT.

Authors:
; ;  [1];  [2]
  1. Department of Materials Science, Wakayama University, 930 Sakaedani, Wakayama 640-8510 (Japan)
  2. Department of Physics, Wakayama University, 930 Sakaedani, Wakayama 640-8510 (Japan)
Publication Date:
OSTI Identifier:
22611418
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 6; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; AGGLOMERATION; ANNEALING; CARBON NANOTUBES; ENERGY DEPENDENCE; FILMS; IRRADIATION; ONE-DIMENSIONAL CALCULATIONS; RAMAN EFFECT; SCATTERING; SPECTROSCOPY; VACANCIES; X RADIATION

Citation Formats

Murakami, Toshiya, Matsuda, Mitsuaki, Itoh, Chihiro, E-mail: citoh@sys.wakayama-u.ac.jp, and Kisoda, Kenji. Origin of a Raman scattering peak generated in single-walled carbon nanotubes by X-ray irradiation and subsequent thermal annealing. United States: N. p., 2016. Web. doi:10.1063/1.4960728.
Murakami, Toshiya, Matsuda, Mitsuaki, Itoh, Chihiro, E-mail: citoh@sys.wakayama-u.ac.jp, & Kisoda, Kenji. Origin of a Raman scattering peak generated in single-walled carbon nanotubes by X-ray irradiation and subsequent thermal annealing. United States. doi:10.1063/1.4960728.
Murakami, Toshiya, Matsuda, Mitsuaki, Itoh, Chihiro, E-mail: citoh@sys.wakayama-u.ac.jp, and Kisoda, Kenji. Mon . "Origin of a Raman scattering peak generated in single-walled carbon nanotubes by X-ray irradiation and subsequent thermal annealing". United States. doi:10.1063/1.4960728.
@article{osti_22611418,
title = {Origin of a Raman scattering peak generated in single-walled carbon nanotubes by X-ray irradiation and subsequent thermal annealing},
author = {Murakami, Toshiya and Matsuda, Mitsuaki and Itoh, Chihiro, E-mail: citoh@sys.wakayama-u.ac.jp and Kisoda, Kenji},
abstractNote = {We have found that a Raman scattering (RS) peak around 1870 cm{sup −1} was produced by the annealing of the X-ray irradiated film of single-walled carbon nanotubes (SWNTs) at 450 {sup o}C. The intensity of 1870-cm{sup −1} peak showed a maximum at the probe energy of 2.3 eV for the RS spectroscopy with various probe lasers. Both the peak position and the probe-energy dependence were almost identical to those of the one-dimensional carbon chains previously reported in multi-walled carbon nanotubes. Consequently, we concluded that the 1870-cm{sup −1} peak found in the present study is attributed to carbon chains. The formation of carbon chains by the annealing at temperature lower than 500 {sup o}C is firstly reported by the present study. The carbon chains would be formed by aggregation of the interstitial carbons, which are formed as a counterpart of carbon vacancies by X-ray irradiation diffused on SWNT walls. The result indicates that the combination of X-ray irradiation and subsequent thermal annealing is a feasible tool for generating new nanostructures in SWNT.},
doi = {10.1063/1.4960728},
journal = {AIP Advances},
number = 8,
volume = 6,
place = {United States},
year = {Mon Aug 15 00:00:00 EDT 2016},
month = {Mon Aug 15 00:00:00 EDT 2016}
}
  • X-ray induced defects in single-walled (SWCNTs) and double-walled carbon nanotubes (DWCNTs) were characterized by Raman scattering spectroscopy. Frenkel defects, interstitial-vacancy pairs, were revealed to form in both SWCNTs and DWCNTs after X-ray irradiation because these defects were entirely healed by thermal annealing. In order to clarify the structure of the X-ray induced defect in SWCNT and DWCNT, isochronal-annealing experiments were performed on the irradiated samples and the activation energy for defect healing was estimated. The intensity of D band (defect induced band) on Raman spectra was used as a measure of the density of X-ray induced defects. The experimental resultsmore » were in good agreement with the simulated values using second order reaction model, which indicated that the defect healing was determined by the migration energy of interstitials on the carbon layer. We also found that the activation energy for defect healing of SWCNT and DWCNT were around 0.5 eV and 0.32 eV, respectively. The X-ray induced defects in SWCNTs were more stable than those in DWCNTs. Compared these estimated activation energies to previous theoretical reports, we concluded that bridge and/or dumbbell interstitials are formed in both SWCNT and DWCNT by X-ray irradiation.« less
  • Graphical abstract: Display Omitted Highlights: ► Structural stability of carbon nanotubes up to 1800 °C in Argon (∼0.05 MPa). ► Thorough TEM and Raman spectroscopy of as received and heat treated CNTs. ► Analyses on the extent of structural changes during high temperature exposure. ► Discussion on safe upper temperature limit for practical use of SWCNTs and MWCNTs. -- Abstract: Effect of high temperature exposure (up to 1800 °C) on morphology of single- and multi-walled carbon nanotubes in Argon atmosphere has been studied using Raman spectroscopy and transmission electron microscopy. Although, as received nanotubes contained irregular graphene layers and othermore » structural defects, microscopic observations revealed that heat treatment in Argon reduced the defect density and helped proper alignment of graphene layers. Raman spectra of as received and heat treated nanotubes strongly reinforced the microscopic observations. While, D-band to G-band intensity ratio in Raman spectra of 1800 °C heat treated multiwalled nanotubes reduced by ∼43% over as received one, this ratio for heat treated singlewalled nanotubes was ∼27% lower than that of the untreated specimen. Present study suggested that although, multiwalled nanotubes were structurally stable up to 1800 °C in an inert atmosphere having only a few nano-scale defects, singlewalled nanotubes suffered considerable damage at 1800 °C due to much thinner dimension than the former.« less
  • Single-walled carbon nanotubes have been functionalized using an inductively coupled radio-frequency plasma system with SF{sub 6}, O{sub 2} and H{sub 2}O plasmas. Samples were characterized using synchrotron soft X-ray photoemission spectroscopy. The influence of plasma power has been investigated along with the effect of gaseous mixtures. It has been found that oxygen has a strong influence over the extent of fluorination both as an impurity in the SF{sub 6} plasma and in the form of surface oxygen content on the nanotubes prior to exposure. The presence of sulfur in samples after exposure has until now been considered non-existent but usingmore » the synchrotron source, its presence has been noted in very small concentrations.« less
  • No abstract prepared.
  • Using electron diffraction on freestanding single-walled carbon nanotubes, we have determined the structural indices (n,m) of tubes in the diameter range from 1.4 to 3 nm. On the same freestanding tubes, we have recorded Raman spectra of the tangential modes and the radial breathing mode. For the smaller diameters (1.4-1.7 nm), these measurements confirm previously established radial breathing mode frequency versus diameter relations and would be consistent with the theoretically predicted proportionality to the inverse diameter. However, for extending the relation to larger diameters, either a yet unexplained environmental constant has to be assumed, or the linear relation has tomore » be abandoned.« less