Mobility and bonding transition of C-60 on Pd(110) - art. no. 161403

Mobility and bonding of C-60 on a Pd(110) surface were characterized by var iable temperature scanning tunneling microscopy. Following adsorption at in termediate temperatures (435-485 K) the motion of single molecules could be directly monitored, and the corresponding tracer diffusion barrier was det ermined to be (1.4 +/-0.2) eV, Upon annealing to approximate to 700 K the m olecules undergo an irreversible bonding transition resulting in a second, more strongly bound C-60 Species With different imaging characteristics. Th is is attributed to a local surface reconstruction where C-60 sinks into th e formed microscopic pits. The findings demonstrate that substrate restruct uring may account for the coexistence of distinct C-60 species at surfaces.