| Project/Area Number |
12640488
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 |
ONDA Ken Tokyo Institute of Technology, Chemical Resources Laboratory, Research associate, 資源化学研究所, 助手 (60272712)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2000: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Second Harmonic Generation / surface / electronic excited state / Cu(111) / Ni(111) / benzene / formate / CO / 電子将起状態 |
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| Research Abstract |
In this research, electronic excited states of molecule adsorbed surfaces were studied by nonlinear spectroscopy, such as second harmonic generation (SHG) spectroscopy and sum frequency generation (SFG) spectroscopy. On benzene or CO adsorbed Cu(111) surfaces, SHG spectra of SH wavelength region from 250 nm to 700 nm were measured using femtosecond tunable laser system based on a Ti:sapphire regenerative amplifier system. The new electronic resonance peaks on the clean Cu(111) surface were found on the spectra. One of the peaks was assigned to the resonances between the electronic state on the defect sites and the other peak was assigned to the electronic state which is peculiar to the surface with sub-monolayer benzene adsorption. Time-resolved vibrational measurements were carried out on formate (HCOO) adsorbed on Ni(111) surface by combining the sum-frequency generation (SFG) method and picosecond laser system (time-resolution of 6 ps). Rapid intensity decreas (within the time-resolution) followed by intensity recovery (time-constant of several 10s ps) of CH stretching signal was observed when picosecond 800 nm pulse was irradiated on the sample surface. From the results of temperature and pump fluence dependences of temporal behavior of signal intensity, we concluded that the observed intensity change was induced by non-thermal process.
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