Observation of a new Au ( 111 ) reconstruction at the interface of an adsorbed C 60 overlayer

Abstract

Scanning tunneling microscope studies of monolayer films of C 60 sublimed onto Au ( 111 ) facets reveal a new Au reconstruction at the C 60-Au ( 111 ) interface after annealing to a temperature of 700 K. C 60 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 C 60-Au interface. The observations indicate that the C 60-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 C 60 layer.