Evidence for a trimer in the √3 × √3 -Bi structure on the Si(111) surface by X-ray diffraction under the nearly normal incidence condition

Abstract

The structure of the √3 × √3 -Bi structure on the Si(111) clean surface has been studied using X-ray diffraction under the nearly normal incidence condition. A thin substrate crystal, about 5 μ m in thickness, was used to reduce the background scattering. From the analysis of the intensity distribution of diffraction patterns, evidence for a trimer of Bi atoms was obtained and the distance between Bi atoms forming the trimer was found to be 3.10±0.1 Å.