Ab initio calculation of the structure, the electronic states and the phonon dispersion of the Si(111)-(2 × 1) surface

Zitzlsperger, M; Honke, R.; Pavone, P.; Schröder, U.

doi:10.1016/s0039-6028(96)01373-8

Cited by 24 publications

(24 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both configurations are quite similar and first-principles calculations predict them to be almost degenerate in energy and separated by a very small energy barrier. 71,72 Experimentally, the positive-tilt structure has been traditionally favored. [68][69][70] In the case of the Si͑553͒ stepped surface, our calculations predict the negative-tilt structure to be slightly more stable.…”

Section: Structural Models: a Labeling Schemementioning

confidence: 99%

“…[68][69][70] However, first-principles DFT calculations predict both structure to be very close in energy and there are conflicting claims about which of them is more stable. 71,72 We now proceed to make all possible substitutions of silicon by gold in the surface bilayer. This gives rise to nine different models for the Si͑553͒-Au reconstructions that we name pX, with X = 1 corresponding to a substitution at the step edge and X Ͼ 1 to a substitution in the terrace.…”

Section: B Restricted Search: Structures Based On the -Bonded Chainmentioning

confidence: 99%

See 1 more Smart Citation

Systematic investigation of the structure of the Si(553)-Au surface from first principles

Riikonen

Sánchez‐Portal

2008

Phys. Rev. B

View full text Add to dashboard Cite

We present here a comprehensive search for the structure of the Si͑553͒-Au reconstruction. More than 200 different trial structures have been studied using first-principles density-functional calculations with the SIESTA code. An iterative procedure, with a step-by-step increase in the accuracy and computational cost of the calculations, was used to allow for the study of this large number of configurations. We have considered reconstructions restricted to the topmost bilayer and studied two types: ͑i͒ "flat" surface-bilayer models, where atoms at the topmost bilayer present different coordinations and registries with the underlying bulk, and ͑ii͒ nine different models based on the substitution of a silicon atom by a gold atom in different positions of a -bonded chain reconstruction of the Si͑553͒ surface. We have developed a compact notation that allows us to label and identify all these structures. This is very useful for the automatic generation of trial geometries and for counting the number of inequivalent structures, i.e., structures that have different bonding topologies. The most stable models are those that exhibit a honeycomb-chain structure at the step edge. One of our models ͑model "f2"͒ reproduces the main features of the room temperature photoemission and scanning-tunneling microscopy data. Thus, we conclude that this model is a good candidate for the high temperature structure of the Si͑553͒-Au surface.

show abstract

Section: Structural Models: a Labeling Schemementioning

confidence: 99%

Section: B Restricted Search: Structures Based On the -Bonded Chainmentioning

confidence: 99%

Systematic investigation of the structure of the Si(553)-Au surface from first principles

Riikonen

Sánchez‐Portal

2008

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…Its atomic structure has been computed from low-energy electron diffraction (LEED) data [2][3][4] and using density functional theory (DFT) total energy methods. [5][6][7][8] In the original model, 1 atoms in the π chain lie in the same horizontal plane; however, this structure was shown to be incompatible with LEED data 2 and a buckled π chain model was proposed. The two silicon atoms in each unit cell of the π chains are inequivalent, even in the Pandey model.…”

Section: Introductionmentioning

confidence: 99%

“…Bond lengths derived from the relaxed ±MP structures are given in Table I, where they are compared to bond lengths derived from the most recent analysis of LEED data for this surface 4 and a previous DFT calculation. 8 When bond lengths for the +MP structure in Table I from the DFT calculation, hybrid DFT calculation, and LEED analysis are compared, most bond lengths from LEED lie between the DFT and hybrid DFT values. This is to be expected since hybrid DFT and DFT, respectively, generally overestimate or underestimate experimentally determined bond lengths by a several hundredths of anÅ.…”

Section: Introductionmentioning

confidence: 99%

Optical and phonon excitations of modified Pandey chains at the Si(111)-2×1 surface

2011

View full text Add to dashboard Cite

The modified Pandey π -bonded chain structure for the (2×1) reconstruction of the Si(111) surface has two nearly degenerate structures in which one or the other of two atoms in the π chain is the outermost atom at the surface. Recent experimental data suggest that both structures can be found on a single Si(111) surface. Surface structures, reflectance anisotropy spectra, and the phonon contribution to the surface conductivity are calculated using a hybrid density functional theory (DFT) method. The modified Pandey chain with a positive tilt of the atoms in the π chain has the lowest energy. A phonon around 50 meV polarized parallel to the π chains has anomalously large, anisotropic Born effective charges and dominates the conductivity. The hybrid DFT approach is suitable for calculating excitations in complex surface and interface structures with large unit cells.

show abstract

“…The less stable of these two configurations is surface atom, it is reasonable to expect the coexistence of both tilt directions at the surface, possibly with thermal flipping between the two structures. A more accurate theoretical calculation based on first principles was performed by Zitzlsperger et al [18]. Similar results were obtained, with two minima differing by only 0.0027 eV per surface atom and separated by a barrier of at most 0.037 eV/surface atom; they exhibit larger tilts of b 1 = 0.44 Å and b 1 = -0.50 Å for the "positive tilt" (second best) and "negative tilt" (best) configurations, respectively.…”

Section: Introductionmentioning

confidence: 99%

Atomic structure of the cleavedSi(111)−(2×1)surface refined by dynamical LEED

Xu¹,

Deng²,

Yu³

et al. 2004

Phys. Rev. B

View full text Add to dashboard Cite

New or modified models have been proposed for the much-studied Si(111)-(2x1) surface structure, including: a reverse-tilted π-bonded chain model (by Zitzlsperger et al); a three-bond scission model (by Haneman et al); and a π-bonded chain model with enhanced vibrations (present work). These models are compared here to the generally accepted modified π-bonded chain model (by Himpsel et al, 1984), by analyzing low-energy electron diffraction (LEED) I-V curves measured earlier. Using the efficient automated tensor LEED technique, the models can be refined to a much greater degree than with earlier methods of LEED analysis. This study distinctly favors the earlier modified π-bonded chain model, but with strongly enhanced vibrations.To compare models that have different numbers of adjustable free parameters a Hamilton ratio test is used: it can distinguish between improvement due to a better model and improvement due only to more parameters.

show abstract

Ab initio calculation of the structure, the electronic states and the phonon dispersion of the Si(111)-(2 × 1) surface

Cited by 24 publications

References 19 publications

Systematic investigation of the structure of the Si(553)-Au surface from first principles

Systematic investigation of the structure of the Si(553)-Au surface from first principles

Optical and phonon excitations of modified Pandey chains at the Si(111)-2×1 surface

Atomic structure of the cleavedSi(111)−(2×1)surface refined by dynamical LEED

Contact Info

Product

Resources

About