Abstract
We investigate the physical parameters controlling the low-energy screening in carbon nanotubes via electron energy loss spectroscopy and inelastic X-ray scattering. Two plasmon-like features are observed, one near 9 eV (the so-called π plasmon) and one near 20 eV (the so-called π + σ plasmon). At large nanotube diameters, the π + σ plasmon energies are found to depend on the number of walls and not on the radius or chiral vector. The observed shift with number of walls indicates a change in the strength of the screening and in the effective interaction at inter-atomic distances; thus this result suggests a mechanism for tuning the properties of nanotubes.
| Original language | English |
|---|---|
| Pages (from-to) | 162-168 |
| Number of pages | 7 |
| Journal | Carbon |
| Volume | 47 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2009 |
Funding
The authors thank C.C. Homes and L. Carr for optical characterization of the samples, A. Stein for electron microprobe pictures of the samples and J. Fink for helpful discussions. Work performed at BNL was supported by US DOE, Division of Materials Science and Engineering, under Contract No. DE-AC02-98CH10886 and partially by DOE-CMSN. Use of the Advanced Photon Source was supported by the US DOE, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Research performed at ORNL was sponsored by the Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, US DOE, under contract DE-AC05-00OR22725. The contribution by GE and DHL was supported by the Division of Materials Sciences and Engineering, Basic Energy Sciences, US Department of Energy, under Contract DE-AC05-00OR22725.