Structural investigation of the quasi-one-dimensional reconstructions induced by Eu adsorption on a Si(111) surface

Journal Article · Tue Nov 15 04:00:00 EST 2005 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.72.195342· OSTI ID:20719832

Sakamoto, Kazuyuki ^[1]; Pick, A; Uhrberg, R I.G. ^[2]

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1. Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan)
2. Department of Physics and Measurement Technology, Linkoeping University, S-581 83 Linkoeping (Sweden)

The surface structures of the (quasi-)one-dimensional reconstructions induced by the adsorption of Eu on Si(111) have been investigated by low-energy electron diffraction (LEED) and high-resolution core-level photoelectron spectroscopy. Different phases were observed in LEED depending on the Eu coverage. The lowest coverage phase has a (3x2) periodicity, and the highest coverage phase has a (2x1) one. Of the intermediate phases, the LEED pattern of the so-called (5x1) surface indicates that this surface has actually a (5x4) periodicity. The Eu 4f core-level spectra show that the Eu coverages of the (3x2) (5x4), and (2x1) phases are 1/6 monolayer (ML), 0.3 ML, and 0.5 ML, respectively, and that the valence state of the adsorbate is 2+ in all these three phases. In the Si 2p core-level spectra, three surface components were observed in both the lowest and highest coverage phases. By considering the energy shift and intensity of each surface component, we conclude that the structure of the (3x2) phase is basically the same as that of the honeycomb-chain-channel model, and that the (2x1) phase is formed by {pi}-bonded Seiwatz Si chains. Regarding the (5x4) phase, two extra Si 2p surface components were observed together with the three components observed in the two end phases. Taking the energy shifts and intensities of the extra surface components into account, we propose a structural model of the (5x4) phase.

• OSTI ID: 20719832
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 19 Vol. 72; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ADSORPTION
ELECTRON DIFFRACTION
EUROPIUM
LAYERS
PERIODICITY
PHOTOELECTRON SPECTROSCOPY
SEMICONDUCTOR MATERIALS
SILICON
STRUCTURAL MODELS
SURFACES
VALENCE