1996 Fiscal Year Final Research Report Summary
Optical Properties of Single-Wall Carbon Nanotubes
| Project/Area Number |
07640432
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | Tohoku University |
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Principal Investigator |
KASUYA Atsuo Institute for Materilas Research, Tohoku University, Assistant Professor, 金属材料研究所, 助教授 (10005986)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUSHIMA Michiko School of Science and Engineering, Ishinomaki Senshu Univ., Assistant Professor, 理工学部, 助教授 (20228894)
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| Project Period (FY) |
1995 – 1996
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| Keywords | nanotube / carbon cluster / raman scattering / graphite |
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| Research Abstract |
Raman scattering spectra of single-wall nanotubes with mean radii 0.55,0.65 and 1.0 nm show size-dependent multiple splittings of the optical phonon peak corresponding to E_<2g> mode in graphite. These splittings constitute the first experimental evidence for the unique feature of nanotubes that they exhibit discrete and diameter-dependent dispersions arising from their cylindrical symmetry. The observed dispersion is well explained on the basis of graphite, and shows possibilities of predicting and controlling the basic property of nanotubes in the zone-folding scheme.
Resonant Raman scattering from optical phonons in single-wall nanotubes of mean diamater 1.1 nm has been measured in the wavelength of incident laser beam between 450 nm and 800 nm. The scattering intensities exhibit anomalies in the vicinity of 690 nm, being a minimum in the longitudinal components and a maximum in the transverse. Our optical transmission measurement also exhibits a dip in the same photon energy range. The anomalies are caused by the incident laser beam resonant with the zone-folded electronic structures in nanotubes. These results constitute a direct experimental evidence of the critical point in the density of ststes produced by the cylindrical symmetry of nanotubes.
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