STRUCTURE DETERMINATION OF THE GE(111)-2 X 1-SB SURFACE USING X-RAY-DIFFRACTION

The atomic structure of the 2x1 reconstruction induced by the adsorption of Sb on the Ge(111) surface has been determined by X-ray diffraction. The projection of the adsorption sites onto the surface plane was derived from the in-plane structure factor amplitudes. The heights of the Sb atoms above the surface plane and their precise positions relative to the substrate lattice were obtained from scans along the integer-order rods of scattering perpendicular to the surface. The adsorbed Sb atoms are found to form three domains of zig-zag chains, saturating the dangling bonds of the Ge atoms in the top layer. The chains are tilted by 5.6(8)-degrees.