Hösler, Wolfgang; Moritz, Wolfgang
LEED analysis of a dense lead monolayer on copper (100).
In: Surface Science, Vol. 175, Nr. 1: S. 63-77
A LEED intensity analysis is reported for the c(5√2 × √2)R45° structure, which is formed by a dense lead monolayer on the (100) surface of copper. Evidence was found that the adsorbate atoms do not arrange pseudo-hexagonally (i.e. without sixfold intra-layer coordination) as expected for a dense two-dimensional package. It was confirmed that the lead atoms still tend to occupy the hollow sites of the (100) surface and arrange in the narrow domains of a strained c(2 × 2) structure. These domains are regularly intersected by dislocation lines, so that adjacent domains are in antiphase position. Within this arrangement the adsorbate atoms are mutually equidistant with closer spacings than in bulk lead. The growth of the monolayer and the epitaxial growth of lead on copper (100) in Stranski-Krastanov mode are correlated to this structure.