Si(111)-(√3≤ √3≤)Ag surface structure studied by impact-collision ion-scattering spectrometry

Abstract
Using the technique of impact-collision ion-scattering spectrometry, we showed that the geometry of the Si(111)-(√3 × √3 )Ag surface consists of Si honeycomb on top of Ag trimers. The separation of the Si and Ag layers is 0.7±0.3 Å and the Si-Ag bond length is 2.73±0.3 Å. We also observed, for the first time, type-A and type-B arrangements of the Si and Ag atoms on the surface, with type B being type A rotated 180° about the surface normal.