Observation of a new Au ( 111 ) reconstruction at the interface of an adsorbed C₆₀ 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 ≈ 1 Å. and a periodicity of 90-160 Å. 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. © 1993.