Reconstructions of C₆₀ on the Ag(111)1x1 surface

We report the scanning tunneling microscope (STM) study of the C₆₀ adsorption on the Ag(111)1x1 surface. The well-ordered C₆₀ monolayer with good quality was obtained by briefly annealing the multilayer C₆₀ at approximately 300°C. It is concluded that the (2√3)x(2√3)R30° reconstruction is energetically the most stable phase, while two other phases, 'hex-a' and 'hex-b' phases, are also observed, rotated by approximately 12.5 ± 1.5° and 47.5 ± 1.5° with respect to the stable (2√3)x(2√3)R30° phase. It is suggested that some specific stable adsorption sites are responsible for the pinning and growth of these 'hex-a' and 'hex-b' phases. Orientational ordering is also documented based on the observed high resolution structures.