| Project/Area Number |
02452141
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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 |
電子材料工学
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| Research Institution | Hokkaido University |
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Principal Investigator |
MUKASA Koichi Fac., of Eng., Hokkaido Univ., Professor, 工学部, 教授 (00001280)
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| Co-Investigator(Kenkyū-buntansha) |
ARAHISO Tsunehisa Research Inst., of Appl., Elect., Hokkaido Univ., Associ., Professor, 応用電気研究所, 助教授 (30151145)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1991: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1990: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | LB monolayer / IETS / Sn, Pb electrode / Tunnel junction / Oxide phonon / Arachidic acid / Molecular vibration / charging / フォノン |
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| Research Abstract |
The aim of this research is to study a metal/LB monolayer interface, that is, to know how a LB monolayer would be adsorbed on a metal (oxide).
The results we researched are as follows ;
1. We constructed Inelastic Electron Tunneling Spectroscopy (IETS) measuring system, by which we can observe metal (oxide) phonon and molecular vibration peaks in a metal-insulator- metal tunnel jonction.
2. We prepared Sn, Pb thin films, that would be used as substrates on which a LB monolayer could be transfered, Sn/SnO_2/Pb, Pb/PbO /Pb produced by two kinds of oxidation procedures (e. g. by varying humidity condition). And we observed Sn, Pb oxide phonon spectra. The reason why we did this experiments is to grasp the surface condition of the metals for a LB monolayer to be transfered. From these measurements, we obtained results below.
(1) The contours of PbO phonons do not change with humidity condition. The molecular vibration peaks are not observed, even if organic molecules are doped into the metal/metal oxide interface.
(2) SnO_2 phonons are strongly affected by humidity condition. And in the higher bias region the molecular vibration peaks are observed.
Therefore we used Sn as the base electrode of a tunnel junction to observe molecular vibration peaks of LB monolayer. From the experimental results above mentioned, we prepared Sn/SnO_2/Ar_2Co/Pb tunnel junctions, and observed the tunnel spectra. We recognized that tunneling is the dominant electron transfer in this tunnel junction from the measurement of supercnducting Pb energy gap. Further we measured the tunnel spectra in the higher bias region. As the result, 'run-dependent' tunnel spectra were observed in the same tunnel junction. This would probably be attributed to the charging with enhancement of permanent dipole of a LB monolayer by alignment of the constituents.
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