| Project/Area Number |
15350008
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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 | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HIROSHI Kondoh The University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (80302800)
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| Co-Investigator(Kenkyū-buntansha) |
OHTA Toshiaki The University of Tokyo, Graduate School of Science, Professor, 大学院・理学系研究科, 教授 (80011675)
AMEMIYA Kenta The University of Tokyo, Graduate School of Science, Research Associate, 大学院・理学系研究科, 助手 (80313196)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥15,300,000 (Direct Cost: ¥15,300,000)
Fiscal Year 2004: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥12,100,000 (Direct Cost: ¥12,100,000)
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| Keywords | standing wave technique / ultra-soft x-ray / organic thin film / azobenzene / structural analysis / 液晶 |
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| Research Abstract |
This project aims (1)development of a structural analysis technique that gives information on vertical locations of atoms in organic thin films formed on super lattice substrates based on standing wave (SW) method using ultra-soft x-rays whose wave lengths are longer than 20Å and (2)its application to structural analysis studies on actual organic thin films. The characteristic of our approach is detection of photoelectrons emitted from the atom of interest induced by the SW field to obtain information of location from the scattered plane. In the first year of this project, we confirmed generation of SWs from the combination of the ultra soft x-rays and the super lattice substrate (W/C)_<80> (d=30.9Å) and demonstrated that structural information can be obtained with reasonably good accuracy (0.5Å) from measurements and analyses of photoelectron-yield SW profiles. In the second year, we applied this technique to structural analyses of organic thin films combining with x-ray absorption sp
… More
ectroscopy that gives information on molecular orientation.
Organic thin films studied here are monolayers of a long alkyl carbonic acid including an azobenzene unit. We focused on how the structure of the monolayer is changed by irradiation of UV light via photo-isomerization of the azobenzene unit. Before UV irradiation, the trans-form molecules are aligned with a tilt angle of ca. 50° from the surface normal and the center of the two N atoms in the azobenzene unit is located at 10.3 Å above the substrate surface. From detailed experiments it was found that UV irradiation (375 nm) causes no change in the structure below the N-atom level but bent of the upper part resulting in more standing-up configuration with a tilt angle of 30° from the surface normal. Also, the conjugated plane of azobenzene was found to stand up more by irradiation. Although organic thin films including azobenzene have been extensively studied so far, this is the first study that elucidates the structural change induced by the photo-isomerization of azobenzene. This technique will be a powerful tool as a structure analysis technique suitable for organic thin films. Less
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