2007 Fiscal Year Final Research Report Summary
Unconventional Electronic and Magnetic Properties of Carbon-Based Nano-π-electron System
| Project/Area Number |
15105005
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| Research Category |
Grant-in-Aid for Scientific Research (S)
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| Allocation Type | Single-year Grants |
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| Research Field |
Functional materials chemistry
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
ENOKI Toshiaki Tokyo Institute of Technology, Graduate School of Science and Engineering, Professor (10113424)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUI Ken-ichi Tokyo Institute of Technology, Graduate School of Science and Engineering, Associate Professor (60262143)
MIYAZAKI Akira Tokyo Institute of Technology, Graduate School of Science and Engineering, Research Associate (40251607)
TAKAI Kazuyuki Tokyo Institute of Technology, Graduate School of Science and Engineering, Research Associate (80334514)
HARIGAYA Kikuo Tokyo Institute of Technology, Advanced Industrial Science And Technology (AIST), Senior Researcher (00357823)
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| Project Period (FY) |
2003 – 2007
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| Keywords | nanographene / molecular magnetism / scanning tunneling microscopy / graphene / nanoporus carbon / gas adsorption / charge transfer interaction / host-guest interaction |
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| Research Abstract |
(1) Holes are created on HOPG substrates by heat-treatment in the atmosphere with a small oxygen concentration. The obtained holes have geometry with directional dependence between zigzag and armchair edges. Using the edges of the holes, the correlation of the electronic structure and the edge structure is investigated by means of UHV-STM. Around the graphene edges, a hexagonal superstructure deformed in three fold symmetry was observed.
(2) Nanographene ribbons, nanographene islands, nanoholes on a graphene sheet are created using electron beam lithography and oxygen plasma etching technique with thin layer graphene.
(3) The magnetic properties was investigated for potassium adsorbed into nanoporous activated carbon fibers (ACFs) which form 3D disordered network of nanographite domains. Two kinds of potassium species are created in the nanopores; charge transfer species electronically interacting with the π-electrons of nanpgraphene sheets and neutral potassium species merely physisorbe
… More
d into the nanopores. Charge transfer from the potassium to the nanographene reduces the concentration of the edge-state spins as a consequence of the upshift of the Fermi energy. The neutral potassium species form antiferromagnetic clusters, in which potassium atoms are coupled strongly with each other through exchange interactions.
(4) The argon atoms adsorbed in the nanopores in ACFs mechanically compress the nanographite domains below the boiling point, resulting in the reduction of the inter-nanographene distance. The reduction of the distance induces the antiferromagnetic short range ordering of the edge-state spins in a nanographite domain.
(5) The adsorption of acid molecules into the nanopores of ACFs modifies the magnetism of the edge-state spins in a manner, in which the charge transfer interaction and the mechanical effect works cooperatively or compete depending on their oxidation ability. Hydrochloric acid adsorbed in the nanopores works mechanically to reduce the magnetic moment of the edge-state spins. Nitric acid having the oxidation ability changes the magnetism of the edge-state spins in a complicated way depending on the content of water in the acid. Less
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[Presentation] ナノダイヤとその周辺2008
Author(s)
T. Enoki
Organizer
新規事業研究会
Place of Presentation
Tokyo (Japan)
Year and Date
2008-03-08
Description
「研究成果報告書概要(欧文)」より
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[Presentation] 炭素でマグネットをつくる2007
Author(s)
T. Enoki
Organizer
日本学術会議 「科学の教育・啓発活動分科会」
Place of Presentation
Sendai (Japann)
Year and Date
2007-10-26
Description
「研究成果報告書概要(欧文)」より
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[Book] 表面科学29(5)2008
Author(s)
榎敏明, 小林陽介, 福井賢一
Total Pages
304-309
Publisher
日本表面科学学会
Description
「研究成果報告書概要(和文)」より
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[Book] 炭素の辞典2007
Author(s)
伊与田正彦, 榎敏明, 玉浦裕
Total Pages
660
Publisher
朝倉書店
Description
「研究成果報告書概要(和文)」より
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