1995 Fiscal Year Final Research Report Summary
Developement of X-ray Excited Scanning Tunneling Spectroscopy and Application to One-Atom Detection
| Project/Area Number |
06453109
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | Institute for Materials Research, Tohoku University |
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Principal Investigator |
HIROKAWA Kichinosuke Institute for Materials Research Tohoku Univ. Professor, 金属材料研究所, 教授 (00005852)
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| Co-Investigator(Kenkyū-buntansha) |
TSUJI Kouichi Institute for Materials Research Tohoku Univ. Associate, 金属材料研究所, 助手 (30241566)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Total Reflection / X-ray Analysis / STM / elemental Analysis / x-ray fluorescence / x-ray Photoelectron / surface Analysis / micro-analysis |
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| Research Abstract |
We challenged the experiments combining the x-ray analysis and the scanning tunneling microscope (STM) for the first time. Therefore, we had to investigate the optimal experimental conditions, the origin of the obtained signal, and the information which was contained in the signal, step by step. Although we could not obtain the good results for more than 1 year.
We found that the STM tip current was measured when the x-rays irradiated the sample's surface under that condition where the usual tunnel current could not be detected. We refereed to this current as the x-ray excited current. Next, we investigated the dependencies of the x-ray excited current on the incident angle of the x-rays, the kind of the gases, the gas pressure, the bias voltage, the x-ray intensity, and kind of the sample. As a result, it was found that the x-ray excited current originated from the electrons emitted from the sample's surface by x-ray irradiation, and that the electrons ionized the gaseous atoms and molecules and produced many electrons when the electrons approached toward the molecules and produced many electrons approached toward the STM tip. Now we have tried the micro-analysis by measuring the x-ray excited current.
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