2012 Fiscal Year Final Research Report
Elucidation of self-vibration phenomenon of carbon nanotubes in magnetic field and its application to nano-sensing
| Project/Area Number |
23656060
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Applied physics, general
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| Research Institution | Nagoya University |
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Principal Investigator |
SAITO Yahachi 名古屋大学, 工学研究科, 教授 (90144203)
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| Co-Investigator(Kenkyū-buntansha) |
ASAKA Koji 名古屋大学, 工学研究科, 講師 (50361316)
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| Project Period (FY) |
2011 – 2012
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| Keywords | カーボンナノチューブ / 電子放出 / 振動 / 電子顕微鏡 / 電界 / 磁界 / ローレンツ力 |
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| Research Abstract |
In-situ transmission electron microscopy (TEM) and scanning electron microscopy (SEM) of carbon nanotube (CNT) field electron emitters have been carried out in order to clarify the origin of spontaneous vibration with large amplitude. In TEM, neither field emission current nor applied voltage were decisive factors for the onset of the spontaneous vibration. Instead, it was found that the orientation of the CNT against the counter electrode was important, i.e., the spontaneous vibration was observed only when the CNT bent more than 50° by the applied electric field. For CNTs which showed spontaneous vibration, a correlation between the onset voltages for vibration and the diameter of CNTs are clearly found, but the length of CNTs showed no effect on the onset voltage. In SEM, on the other hand, even CNT emitters which bent more than 50° did not show any spontaneous vibration at all. Since the magnetic field at the SEM sample stage is much smaller than that at TEM sample stage, the difference in the CNT behavior between TEM and SEM indicates the role of the magnetic field in the induction of the spontaneous vibration; i.e., the Lorentz force between the electric current through the CNT and the magnetic field is the origin of the induction of large-amplitude vibration.
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