| Project/Area Number |
60850140
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
工業分析化学
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| Research Institution | University of Tokyo |
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Principal Investigator |
GOHSHI Yohichi Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 教授 (90111468)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUSHIMA Sei Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 助手
MIYAMURA Kazuo Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 助手 (40157673)
IIDA Atsuo National Laboratory for High Energy Physics; Photon Factory, 放射光実験施設, 助教授 (10143398)
SAWADA Tsuguo Univ. of Tokyo; Dept. of Ind. Chem., 工学部, 助教授 (90011105)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥26,000,000 (Direct Cost: ¥26,000,000)
Fiscal Year 1986: ¥11,000,000 (Direct Cost: ¥11,000,000)
Fiscal Year 1985: ¥15,000,000 (Direct Cost: ¥15,000,000)
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| Keywords | Tunneling effect / Scanning Tunneling microscope / Nondestructive analysis / Surface analysis / Graphite / Piezo electric element / 非弾性トンネル分光 / 非弾性トンネルスペクトル |
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| Research Abstract |
The following results were obtained in this research project.
1. Development of a tip scanning mechanism for an analytical scanning tunneling microscope in tunneling spectroscopy, the position of a probe tip has to be controlled with the precision of 0.1nm. A Z axis scanning device with three precision grades was designed using stacked PZT Piezo electric elements. An inchworm mechanism ( m order),a coarse positioning mechanism with simple expanding-contracting action (to 600nm) and a fine positioning mechanism using a cubic Piezo electric element (to <0.01nm, X, Y, Z axes).
2. High vacuum, low temperature chamber: A high vacuum chamber was designed and constructed, which contained a cooling system of liquid nitrogen temperature for the tunneling unit. All the components except a roughening pump system, ie, an ion pump for high vacuum and a lig N_2 cooling shroud etcwere designed as small as possible. This vacuum chamber was set with very high stability on an air suspendend vibration insu
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lation stage.
3. Tip: Wolfram wire was etched electrically to prepare a sharp piece of a tunneling tip. With this method, a tip of 100-200nm size was obtained and it has satisfactory characteristics. Another types of a tip, Pt (Ir) and semiconducting diamond were also tested.
4. Measuring and controll system: All the measuring process except setting with the coarse positioning mechanism were controlled with a personal computer. The system was designed by this research group.
5. Results of measurements: a thermal drift of 4A^^゜/min in air was attained in a room with a conventional air conditioner. Under these conditions, we succeeded to obtain a STMimage of graphite. A spectrum of first derivative was obtained by modulating the tunneling voltage with 3.5mv 1.47KHz sinusoidal waves. A spectrum of second derivative whichcorresponded to a vibrational spectrum was expected to be derived as a second harmonic wave. Unfortunately at present, the noise level of the system was too high. Therefore, further improvements in S/N are needed. Less
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