Structural studies of Si (111) 2 × 1 surfaces using low-energy electron diffraction

Abstract

The structure of the Si(111)2\ifmmode\times\else\texttimes\fi{}1 surface is studied using dynamic low-energy electron diffraction analysis at three different off-normal electron incidence angles, with emphasis on the $\ensuremath{\pi}$-bond chain model. The optimum $\ensuremath{\pi}$-bond chain geometry has a buckling of 0.35 \AA{} between the two chain atoms and a large distortion in the subsurface layer. The bond length of surface chains is determined to be 2.25\ifmmode\pm\else\textpm\fi{}0.02 \AA{} by detailed analysis. We compare our results with those of other authors.