Sm- and Yb-induced reconstructions of the Si(111) surface

Wigren, C.; Andersen, J. N.; Nyholm, R.; Göthelid, Mats; Hammar, Mattias; Törnevik, C.; Karlsson, Ulf O.

doi:10.1103/physrevb.48.11014

Cited by 62 publications

(38 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of the S4 and S5 components, S4 was also reported in the Si 2p core-level study of divalent rare-earth metals ͑Sm and Yb͒ adsorbed Si(111)-(5ϫ1) surfaces, which were also proposed to be formed by a combination of the rare-earth metals induced (3ϫ''2''͒ and (2ϫ1) phases. 25,26 In this previous study, S4 is attributed to originate from the dimers of the first layer Si atoms. Here, we notice that the structural models of the (3ϫ''2''͒ and (2ϫ1) phases used in this previous study are different from the HCC and Seiwatz models, i.e., Sm and Yb atoms were proposed to be adsorbed in the bridge sites of an ideal Si͑111͒-͑1ϫ1) surface.…”

Section: B "5ã''2''… Phasementioning

confidence: 84%

Structural investigation of Ca/Si(111) surfaces

et al. 2002

View full text Add to dashboard Cite

The surface structures of different Ca/Si͑111͒ surfaces were studied by low-energy electron diffraction ͑LEED͒ and high-resolution core-level photoelectron spectroscopy. Five different phases were observed in LEED depending on the Ca coverage. The lowest coverage phase has both (3ϫ2) and c(6ϫ2) periodicities, and the highest coverage phase has a (2ϫ1) periodicity. The LEED patterns of the three intermediate phases were (5ϫ2), (7ϫ1), and (9ϫ1). In the Si 2p core-level spectra, three surface components were observed in both the lowest and highest coverage phases. These three surface components were also observed in each intermediate phase together with two other components. The presence of the two extra components indicates that the intermediate phases are not completely described by simple combinations of the two end phases as suggested in the literature. By considering the energy shift and intensity of each surface component, we conclude that the structure of the (3ϫ2) phase is basically the same as that of the honeycomb-chain-channel model with a Ca coverage of 1/6 ML, and the (2ϫ1) phase is formed by -bonded Seiwatz Si chains with a coverage of 0.5 ML. Moreover, taking the energy shifts and intensities of the extra surface components into account, we propose a structural model of the (5ϫ2) phase, whose Ca coverage is 0.3 ML.

show abstract

Section: B "5ã''2''… Phasementioning

confidence: 84%

Structural investigation of Ca/Si(111) surfaces

et al. 2002

View full text Add to dashboard Cite

show abstract

“…Ca, 20,[30][31][32]36,37 Sr, 38 Yb, 7,8 and Eu 10-13 form a ͑2 ϫ 1͒ reconstruction, while the adsorption of Ba leads to a ͑2 ϫ 8͒ reconstruction. 25,39 The origin of this difference was proposed to be either the large ionic radius of Ba that induces a strain relaxation within the ͑2 ϫ 1͒ unit cell, 25 or the disorder of the ϫ8 periodicity caused by defects in the Ca, Sr, Yb, and Eu adsorbed surface.…”

Section: B Eu/ Si"111…-"2 ã 1…mentioning

confidence: 99%

“…From a scientific point of view, these 1D structures have attracted much attention due to the possibility of observing various exotic physical phenomena, such as formations of non-Fermi-liquid-like ground states, Peierls-like phase transitions, or order-disorder transitions. [1][2][3][4][5][6] The 1D and quasi-1D reconstructions formed by the adsorption of rare-earth metals ͑REMs͒ on a Si͑111͒ surface [7][8][9][10][11][12][13][14][15][16] are candidates for such 1D systems.…”

Section: Introductionmentioning

confidence: 99%

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

2005

View full text Add to dashboard Cite

The surface structures of the ͑quasi-͒one-dimensional reconstructions induced by the adsorption of Eu on Si͑111͒ have been investigated by low-energy electron diffraction ͑LEED͒ and high-resolution core-level photoelectron spectroscopy. Different phases were observed in LEED depending on the Eu coverage. The lowest coverage phase has a ͑3 ϫ 2͒ periodicity, and the highest coverage phase has a ͑2 ϫ 1͒ one. Of the intermediate phases, the LEED pattern of the so-called ͑5 ϫ 1͒ surface indicates that this surface has actually a ͑5 ϫ 4͒ periodicity. The Eu 4f core-level spectra show that the Eu coverages of the ͑3 ϫ 2͒, ͑5 ϫ 4͒, and ͑2 ϫ 1͒ phases are 1 / 6 monolayer ͑ML͒, 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 ͑3 ϫ 2͒ phase is basically the same as that of the honeycomb-chain-channel model, and that the ͑2 ϫ 1͒ phase is formed by -bonded Seiwatz Si chains. Regarding the ͑5 ϫ 4͒ 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 ͑5 ϫ 4͒ phase.

show abstract

“…[7][8][9][10][11][12] Of these REM's, Eu has been reported to form a quasi-1D ͑3 ϫ 2͒ reconstruction at a coverage of 1 / 6 ML, and a series of 1D ͓͑n ϫ 1͒ ; n = 5, 7, and 9͔ reconstructions at higher coverages culminating in a ͑2 ϫ 1͒ phase at 0.5 ML. [10][11][12] The lowest coverage ͑3 ϫ 2͒ phase has been proposed to have the same geometric structure as that of alkaline-earth metal ͑AEM͒ induced Si͑111͒-͑3 ϫ 2͒ surfaces ͑Refs.…”

Section: Introductionmentioning

confidence: 99%

Surface electronic structures of the Eu-induced Si(111)-(3×2)and -(2×1)reconstructions

2005

View full text Add to dashboard Cite

The electronic structures of the Eu/ Si͑111͒-͑3 ϫ 2͒ and ͑2 ϫ 1͒ surfaces have been investigated by angleresolved photoelectron spectroscopy. On the ͑3 ϫ 2͒ surface, we identify six surface states in the gap and a pocket of the bulk band projection. Among the five surface states observed in the bulk band gap, the dispersions of three of them agree well with those of the surface states of monovalent atom adsorbed Si͑111͒-͑3 ϫ 1͒ surfaces. The dispersions of the two other surface states observed in the band gap agree well with those observed on the Ca/ Si͑111͒-͑3 ϫ 2͒ surface, which has basically the same structure as that of monovalent atom adsorbed Si͑111͒-͑3 ϫ 1͒ surfaces. Taking these results into account, we conclude that the five surface states observed in the band gap originate from the orbitals of Si atoms that form a honeycomb-chain-channel structure. In the case of the ͑2 ϫ 1͒ surface, two semiconducting states are observed in the bulk band gap. The difference in binding energy of these two states at the ⌫ point agrees well with that of the surface states obtained theoretically for a clean Si͑111͒-͑2 ϫ 1͒ surface with a Seiwatz structure, and the dispersion of the upper state shows good agreement with the corresponding theoretical surface state. These observations indicate that the two surface states in the band gap originate from Si atoms that form a Seiwatz chain. The present results support the structures of the Eu/ Si͑111͒-͑3 ϫ 2͒ and ͑2 ϫ 1͒ surfaces proposed in the literature.

show abstract

Sm- and Yb-induced reconstructions of the Si(111) surface

Cited by 62 publications

References 24 publications

Structural investigation of Ca/Si(111) surfaces

Structural investigation of Ca/Si(111) surfaces

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

Surface electronic structures of the Eu-induced Si(111)-(3×2)and -(2×1)reconstructions

Contact Info

Product

Resources

About