Imperial College London
Professor Nick Quirke

ProfessorNickQuirke

Faculty of Natural Sciences, Department of Chemistry

Emeritus Professor
 
 
 
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Contact

 

+44 (0)20 7594 5844n.quirke

 
 
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Location

 

Molecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Shen:2016:10.1117/12.2236463.,
author = {Shen, Y and Quirke, N and Zerulla, D},
doi = {10.1117/12.2236463.},
journal = {Proceedings of SPIE},
title = {Ultra-low frequency Raman spectroscopy of SWNTs under high pressure},
url = {http://dx.doi.org/10.1117/12.2236463.},
volume = {9932},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Radial deformation phenomena of carbon nanotubes (CNTs) are attracting increased attention because evenminimal changes of the CNT’s cross section can result in significant changes of their electronic and optical properties.It is therefore important to have the ability to sensitively probe and characterize this radial deformation.High pressure Raman spectroscopy offers a general and powerful method to study such effects in SWNTs. In thisexperimental work, we focus in particular on one theoretically predicted Raman vibrational mode, the so-called”Squash Mode” (SM), named after its vibrational mode pattern, which has an E2g symmetry representation andexists at shifts below the radial breathing mode (RBM) region. The Squash mode was predicted to be moresensitive to environmental changes than the RBM.Here we report on a detailed, experimental detection of SMs of aligned SWNT arrays with peaks as close as18 cm−1to the laser excitation energy. Furthermore, we investigate how the SM of aligned CNT arrays reactswhen exposed to a high pressure environment of up to 9 GPa. The results confirm the theoretical predictionsregarding the angular and polarization dependent variations of the SM’s intensity with respect to their excitation.Furthermore, clear Raman upshifts of SM under pressures of up to 9 GPa are presented. The relative changes ofthese upshifts, and hence the sensitivity, are much higher than that of RBMs because of larger radial displacementof some of the participating carbon atoms during the SM vibration.
AU  - Shen,Y
AU  - Quirke,N
AU  - Zerulla,D
DO  - 10.1117/12.2236463.
PY  - 2016///
SN  - 0277-786X
TI  - Ultra-low frequency Raman spectroscopy of SWNTs under high pressure
T2  - Proceedings of SPIE
UR  - http://dx.doi.org/10.1117/12.2236463.
UR  - http://hdl.handle.net/10044/1/41750
VL  - 9932
ER  -
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