Photoelectron diffraction and low energy electron diffraction studies of Cs, K/Si(001) surfaces

Abstract

X-ray photoelectron diffraction patterns of Cs 3d core levels for the full-Cs-coverage Si(001)-2 × 1-Cs surface have been measured and analyzed kinematically. It is found from the analysis that one monolayer of Cs, i.e., Cs/surface-Si ratio of unity, is present over the substrate forming a double-layer (upper and lower) array of atoms. The arrangement of Cs atoms in the double layer is essentially the same as the K double layer for the Si(001)2 × 1-K surface. New surface orders are reported that can be formed by the deposition of Cs or K atoms onto an annealed Si(001) substrate.