| Project/Area Number |
07454070
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Ishinomaki Senshu University |
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Principal Investigator |
MAEDA Toshiteru Faculty of Science & Engineering, Ishinomaki Senshu University, Assitant professor, 理工学部, 講師 (80202307)
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| Co-Investigator(Kenkyū-buntansha) |
NISHINA Yuichiro Faculty of Science & Engineering, Ishinomaki Senshu University, Professor, 理工学部, 教授 (90005851)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥7,800,000 (Direct Cost: ¥7,800,000)
Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1996: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1995: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | small particles / Micro-crusters / Gas evapolation method / Raman scattering / Carbon nanotubes / Phonon dynamics / Luminescence spectroscopy / Spacially resolved spectroscopy / 半導体 |
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| Research Abstract |
We report here some remarkable features we have found during the study on semiconductor (Germanium) small particles and carbon nanotubes.
1. We have found that the structure of Ge small particles prepared with the gas evapolation method is affected by excxited Ar atoms in an atomosphere. Raman spectra of these particles shows the amorphous part in the particle is increased by the excited gas evapolation method.
2. We have observed light emission from Ar atoms, Ge atoms/clusters(Ge_2, and Ge ions during the evaporation process of Ge in an Ar-gas atmosphere of a few Torrs. The Ar(I) lines are observed regardless of whether the crucible is empty or filled with Ge. Ar atoms are excited through discharge intiiated by electrons thermionically emitted from the hot W wire heating the crucible and accelerated by the potential applied to the wire. The Ge lines are stronger for lower Ar pressures and for lower Ge vapor density, while the Ge_2 line is stronger for highr Ar pressures. This shows the existence of atomic processes for the energy transformation from Ar to Ge during the gas evapolation.
3. Raman scattering spectra of single-walled nanotubes with relative small diameter (typically d = 1.1 nm) show size-dependent multiple splittings of the optical phonon peak corresponding to the E_<2g> mode in graphite. This observation is successfully explained by diameter-dependent dispersions of phonons arising from the cylindrical symmetry of the nanotube.
4. Phonon modes in single-walled nanotubes (SWNTs) of carbon are reexamined within the framework of a force constant model. The curvature effect of tubules is discussed by comparing with the results obtained by the zone-folding model. The diameter dependent properties of phonon modes are shown to be useful fo analyzing the size distribution of SWNT in the synthesized samples.
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