THE SYSTEM K AU(111) - ADSORPTION AND SURFACE RESTRUCTURING/

The interaction of the reconstructed Au(111) surface with adsorbed K a toms was analyzed by scanning tunneling microscopy and low-energy elec tron diffraction (LEED). For K coverages between similar to 0.1 and 0. 33 monolayers (ML) the periodicity of the Au(111) Chevron reconstructi on decreases with coverage. The K adatoms form a hexagonal (root 3 x r oot 3)R30 degrees overlayer on the reconstructed substrate at theta(K) approximate to 0.33 ML. For higher K coverages islands of a K-induced reconstruction are formed. The Au(lll) reconstruction is completely l ifted at similar to 0.5 ML K, whereby a (2 X 2) LEED pattern is observ ed.