Br/Si(211)2x1 structure investigated by x-ray standing wave

Abstract

The Br/Si(211)2×1 interface was investigated using the x-ray standing wave technique. Three different Bragg reflections [(111), (220) and (422)] were used to determine the adsorption sites following a triangulation method. In all the interfaces prepared, Br adsorption reverted the 2×1 substrate reconstruction to 1×1. Br atoms occupy different sites depending on the preparation conditions: the conventional atop site of the [111]-like terraces of the surface, and also along the unsaturated dangling bonds of the [100]-like steps present at the surface. A partial occupation of other types of sites has also been detected.