| Project/Area Number |
07554050
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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 | 試験 |
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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 | Tohoku University |
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Principal Investigator |
UEHARA Yoichi Tohoku University, Research Institute of Electrical Communication, Associate Professor, 電気通信研究所, 助教授 (30184964)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1996: ¥500,000 (Direct Cost: ¥500,000)
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| Keywords | STM / Spectroscopy / High spatial resolution measurement / surface science / 光放出 / STM発光分光 / 発光 |
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| Research Abstract |
STM ligth emission spectroscopy is a powerful tool for investigating properties of surface microstructures. Since the beam diameter of electrons from the STM tip is narrower than -1 nm, one can expect to obtain the light emission spectra of individual nanometer-scale structures.
One obstruction to STM light emission spectroscopy with the expected spatial resolution is unintended change of tip position due to ambient temperature fluctuation etc. (tip drift) during spectral measurement. Since STM light emission intensity is weak long exposure time (a few hundred seconds or longer) is required. As result spatial resolution of STM light emission spectroscopy becomes worse than the expected value (the beam diameter).
In this project a new tip position locking mechanism for STM light emission spectroscopy has been developed. The way of the locking is as follows : Let us assume that the total exposure time required to observe emission spectra is nxT (n times T). First topographic image of an area on the sample surface is taken. Then STM light emission spectrum from a microstructure in the area is measured for the time period of T (the exposure time of the spectrum is T). Again topographic image of the area same as that taken before the spectral measurement is observed and the amount of the drift during the exposure is calculated by comparing the two STM images. Then the tip is moved back on the microstructure and the next spectrum is measured. By repeating the above procedure n times and accumulating the spectra STM light emission spectrum corresponding to the exposure time of nxT can be measured with the spatial resolution better than the amount of drift during the time period T.If T is selected enough small STM light emission spectroscopy with high spatial resolution becomes possible.
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