Electronic states and phase transition of one-dimensional nano-structures induced by rare-earth metals on semiconductor surfaces
| Project/Area Number |
17540288
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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 |
Condensed matter physics I
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| Research Institution | Chiba University |
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Principal Investigator |
SAKAMOTO Kazuyuki Chiba University, Graduate School of Advanced Integration Science, Associate Professor (70261542)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,810,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥210,000)
Fiscal Year 2007: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Low-dimensional nano-structures / Phase transition / Photoelectron spectroscopy |
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| Research Abstract |
The electronic structures and atomic structures of the (quasi-)one-dimensional reconstructions induced by the adsorption of Eu on Si(111) have been investigated by photoelectron spectroscopy and low-energy electron diffraction (LEED). The lowest coverage phase has a (3×2) periodicity, and the highest coverage phase has a (2×1) one. The electronic structures of these two phases suggest that the (3×2) phase has a honeycomb-chain-channel structure and the (2×1) has a Seiwatz structure. Of the intermediate phases, the LEED pattern of the so-called (5×1) surface indicates that this surface has actually a (5×4) periodicity. Taking the photoemission results, we have proposed a structural model of this (5×4) phase. Regarding the valence states, the Eu 4f core-level spectra show that they are 2+ in all the Eu induced phases.
The electronic structure of the Yb/Si(111)-(3×2) surface has been investigated using angle-resolved photoelectron spectroscopy. By considering the dispersions of the five surface states observed in the gap of the bulk band projection, we discussed the electronic and atomic structures of this surface.
The coverage-dependent valence state of Tl adsorbed on a Si(111)-(7×7) surface and the coverage dependence of the charge states of surface Si atoms have been investigated by high-resolution core-level photoelectron spectroscopy. Taking the valence state on a (1×1) surface reported in the literature into account, we conclude that the valence state of Tl is 1+, and that the 6s^2 electrons of Tl are inactive as an inert pair in the Tl-Si bonding on a Si(111) surface at a coverage of 1 ML and below. By considering the Si 2p core-level spectra, we have proposed structural models for the Tl/Si(111)-(1×1) and (〓3×〓3) surfaces.
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Report
(4 results)
Research Products
(61 results)
