1998 Fiscal Year Final Research Report Summary
Dynamics of surface electronic excited states
| Project/Area Number |
08404039
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
HIROSE Chiaki Tokyo Institute of Technology Research Laboratory of Resources Utilization Professor, 資源化学研究所, 教授 (70016723)
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| Co-Investigator(Kenkyū-buntansha) |
ONDA Ken Tokyo Institute of Technology Research Laboratory of Resources Utilization Resea, 資源化学研究所, 助手 (60272712)
WADA Akihide Tokyo Institute of Technology Research Laboratory of Resources Utilization Assoc, 資源化学研究所, 助教授 (20202418)
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| Project Period (FY) |
1996 – 1998
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| Keywords | SFG / SHG / ultrafast phenomena / surface / excited state / ultrashort pulse / time-resolved method / lifetime |
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| Research Abstract |
1. Time-resolved SFG observation of transient behavior of CO adsorbed on Ni(111) and NiO(111) surfaces
Transient SFG spectra on CO/Ni(111) and CO/NiO(111) systems under the irradiation by UV and visible picosecond laser pulses as the excitation pulse was measured. It was found that the transient vibrational hand with the lifetime shorter than 30 ps was appeared when the UV pulses was irradiated. The results suggest that the substrate hot electrons generated by the UV pulses could excite the CO stretching vibrational mode by electronic driven process.
2. Time-resolved SFG study of short-lived surface species produced by the intense NIR pulses
Transient species on the formate adsorbed Ni(111) and NiO(111) surfaces produced by the temporal temperature increase due to the picosecond NIR pulse irradiation was observed by the time-resolved SFG method. It was found that the unstable monodentate formate was appeared as the intermediates of the decomposition reaction.
3. Relaxation dynamics of the
… More
water molecule adsorbed on the zeolite OH groups.
The vibrational lifetimes of the species adsorbed on the zeolite OH group was measured by the picosecond IR pump-probe method. The IVR process in the adsorbed water molecule followed by the energy relaxation process to the low-frequency phonon mode of zeolite framework was observed, and the vibrational lifetimes were measured.
4. Excimer lifetime of naphthalene adsorbed on Ni(111) surface
The thickness dependence of lifetime of fluorescence from the naphthalene films adsorbed on Ni(111) surface was measured. The lifetime showed the strong thickness dependence when the thickness was less than 50 nm due to the image dipole interaction between the naphthalene excimer and Ni surface.
5. SHG measurements of the electronic excited states on benzene and naphthalene adsorbed Cu(111) surface
Resonant SHG spectra were measured on the benzene/Cu(111) and naphthalene/Cu(111) systems. For both cases, the resonant peaks showed the blue shifts compared with the resonant frequency of free molecules due to the interaction between the excited states of the molecules and the surface state of Cu(111) surface.
6. Hot electron dynamics of CdO thin film
Femtosecond pump-probe experiments were carried out on the heavily doped n-type CdO thin film. It was observed that the thermalization process of hot electrons generated by the UV femtosecond pulses, and the time constant of electron-lattice thermalization was estimated as 22 ps at the substrate temperature of 30K. Less
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