| Project/Area Number |
10309003
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
広領域
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| Research Institution | Waseda University |
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Principal Investigator |
OSHIMA Chuhei Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (10212333)
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| Co-Investigator(Kenkyū-buntansha) |
NAKADA Kyoko Aoyama Gakuin University, School of Science and Engineering, Lecturer, 理工学部, 講師 (20272742)
ENOKI Toshiaki Tokyo Institute of Technology, Graduate school, Professor, 大学院・理工学研究科, 教授 (10113424)
NAKAO Kenji Tsukuba University, Institute of Materials Science, Professor, 物質工学系, 教授 (30011597)
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| Project Period (FY) |
1998 – 2000
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| Keywords | nanographite / carbon nanoribbon / electronic edge states / Vibrational edge states / pai-electron / spin glass / カーボンナノチューブ |
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| Research Abstract |
We have fabricates carbon nano-ribbons with 1.3 nm width on TiC(557) surface. The phonon spectra showed the quantized phonon modes, and edge phonon modes, of which the vibrational amplitude is localized at the armchair edges. The STM and STS studies indicates that the monolayer graphene/ h-BN/Ni (111) junction exhibiting the incommensurate system is the semiconductor with 2 eV energy gap. Structures, electronic and magnetic properties have been investigated using activated carbon fibers and heat treatment of nano-diamond particles. Activated carbon fibers is featured with a 3D random network of nano-graphite domain, while heat-treatment convert nano-diamond to nano-graphite. Around the insulator-metal transition around 1200 C, edge-state spins form spin glass state.
Nanographite are nanometer-sized graphite fragments, which represent a new class of a mesoscopic system intermediate between aromatic molecules and extended graphite sheets. We investigated theoretically magnetic and transport properties of nanographites. We found that the existence of graphite edges and their shapes strongly affects various properties of nanographite. We have studied the electronic state of nanographite ribbons with a pair of zigzag edges by using the first-principle calculation based on the local density approximation. The edge state, which we predicted within the tight-binding approximation, was reproduced for single-layered and AB-staked zigzag ribbons. Ribbons without hydrogen termination keep the flat form throughout the process of atomic-structure optimization. The dangling-bond state of o-character makes no hybridization with the edge state of π characters.
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