The growth of Co on Cu(111) with Pb as a surfactant was found to be accompanied by a considerable surface reconstruction of (4 x 4) symmetry induced by the surfactant. Its crystallography was investigated by quantitative low-energy electron diffraction for an initial and later stage of growth with deposition of 1.3ML and 7ML of Co, respectively. In the low coverage case, the surface reconstruction was rather similar to that of Pb/Cu. It extended deeply into the substrate with simultaneous minimization of the Pb layer buckling. The structure seemed to be controlled by the predominant fcc-stacking characteristic of this early stage of growth. With further cobalt deposition the type of reconstruction changes. For the 7ML Co film, it was restricted to the Pb and top Co layer only with the buckling of the surfactant layer considerably increased. It was considered that this could be attributed to the slightly different lattice parameters of Cu and Co, although the influences of the different stacking involved could not be ruled out. The top film layer was always reconstructed during the whole growth which might be responsible for the easy exchange processes which take place during the growth and were essential for the layer-by-layer growth as found earlier.

Surfactant-Induced Structures in the Heteroepitaxial Growth of Co on Cu(111). S.Müller, J.E.Prieto, T.Krämer, C.Rath, L.Hammer, R.Miranda, K.Heinz: Journal of Physics - Condensed Matter, 2001, 13[44], 9897-911