OBSERVATION OF A NEW AU(111) RECONSTRUCTION AT THE INTERFACE OF AN ADSORBED C-60 OVERLAYER

Scanning tunneling microscope studies of monolayer films of (C60 sublimed onto Au(111) facets reveal a new Au reconstruction at the C60-Au(111) interface after annealing to a temperature of 700 K. C60 forms two well-ordered hexagonal phases upon which is superimposed a striped texturing with a long-range height modulation of almost-equal-to 1 angstrom and a periodicity of 90-160 angstrom. This texturing is shown to arise from a modification of the reconstruction of clean Au(111) present at the C60-Au interface. The observations indicate that the C60-Au interaction reduces energetic factors favoring compression of the first Au layer resulting in a substantial increase in the unit cell of the Au reconstruction along [110] directions. This decompression of the first Au layer also favors the formation of a commensurate C60 layer.