Determining the atomic structure of the ( 4 × 4 ) silicene layer on Ag(111) by combined grazing-incidence x-ray diffraction measurements and first-principles calculations

A. Curcella (1) , R. Bernard (2) , Y. Borensztein (2) , A. Resta (3) , M. Lazzeri (4) , Geoffroy Prévot (2)

1 INSP - Institut des Nanosciences de Paris
2 INSP-E6 - Physico-chimie et dynamique des surfaces
3 SSOLEIL - Synchrotron SOLEIL
4 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie

From grazing-incidence x-ray diffraction measurements and density functional theory calculations, we have precisely determined the atomic positions of the Si and Ag atoms forming the (4×4) Si/Ag(111) silicene reconstruction. A remarkable agreement is found between the experimental structure factors and the theoretical ones derived from the calculations. Our results confirm the honeycomb structure previously proposed, with a buckling of Si atoms equal to 0.77 Å. The Ag substrate atoms are also relaxed, leading to a nonnegligible elastic deformation energy of the substrate, equal to 43 mJ/m2.

Mots clés: silicene; x-ray diffraction; first principle; an initio

Domaines: Science des matériaux [cond-mat.mtrl-sci]

A. Curcella, R. Bernard, Y. Borensztein, A. Resta, M. Lazzeri, et al.. Determining the atomic structure of the ( 4 × 4 ) silicene layer on Ag(111) by combined grazing-incidence x-ray diffraction measurements and first-principles calculations. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 94 (16), pp.165438. ⟨10.1103/PhysRevB.94.165438⟩. ⟨hal-01400118⟩