Rheed intensity analysis of Si(111)7 × 7 and √3 × √3- Ag surfaces : I. Kinematic diffraction approach

Abstract

Rocking curves of specular spot intensities are measured. The azimuthal angle of incident beam direction is set at 11.5° off the [112̄] direction in order to avoid simultaneous reflections. For a Si(111)7 × 7 surface, the interplanar distance of the first double layer is 0.64 ± 0.05 A ̊ , which is a 18% contraction of the bulk, from the kinematical analysis with six silicon layers. For a √3 × √3- Ag surface, the silver atoms are embedded in the first double layers of the silicon below 0.25 ± 0.05 A ̊ from the surface.