| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Research Abstract |
Although much progress has recently been made in the study of solid surfaces, the process of reactions taking place on the surfaces has not been well understood. This seems to be due to the fact that surface-analysis methods which are selectively sensitive to the outermost surface layer have not been well applied. In this study, we tried to develop a new method of surface analysis with the combination of PIES (Penning ionization electron spectroscopy) and HREELS (high resolution electron energy loss spectroscopy). PIES provides information on the electronic state of the outermost surface layer of solid selectively, whereas HREELS enables us to detect atomic and molecular vibrations at the outermost layer sensitively.
To achieve the above purpose, we designed and constructed an instrument including the appratuses for LEED (low energy electron diffraction), AES (Auger electron spectroscopy), and UPS (ultraviolet photoelectron spectroscopy) together with those for PIES and HREELS. Using th
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is instrument, we studied surfaces of clean Ni(100) and CO adsorbed on it. The structure and atomic composition of the surfaces were investigated by LEED and AES, the electronic state by PIES and UPS, and the vibrational state was examined by HREELS. The measurements of <He^*> PIES gave the following results. On the clean Ni surface the 2s electon of a metastable helium atom transfers to the Ni surface to form a <He^+> ion. Therefore, the corresponding spectrum is similar to that given by INS (ion neutralization spectroscopy). On the adsorbed surface, on the other hand, Penning ionization process takes place because the Ni surface is shielded by CO atoms. In this case, direct information on the electron distribution of individual orbitals exposed outside the adsorbed surface can be obtained by PIES.
In adition to the above study, the characterization of surfaces of various organic thin films was performed by PIES and UPS. It has been confirmed that PIES enables us to detect sensitively the changes in the molecular orientation and electronic state at the outermost surface layer of solid. In particular, the molecular orientation in LB (Langmuir-Blodgett) films noted recently has been found to be directly known by PIES even in the cases of ultra-thin films composed of one to several monolayers. Less
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