Reconstructed surfaces of C60 epitaxial films on KBr(001) substrates were directly observed by atomic force microscopy. The images revealed ridge-like fringes running along the 3 equivalent [1¯10] directions on the face-centered cubic (111) face on the surfaces of C60 thick (> 500nm) films. Molecular-resolution images revealed that the raised fringe region was contracted by about 3% in the [11¯2] direction and that the vertical displacement of the fringe was 0.30nm. The observations suggest a stacking-fault-domain model involving periodic transitions between face-centered cubic (ABCABC… stacking) and hexagonal close-packed (ABAB… stacking) structures. Face-centered cubic surface domains were proposed to exist on the wider areas between fringes on the C60 film surface based on the fact that the fcc bulk structure was energetically slightly more favourable than that of hcp.

Molecularly Resolved Observation of Surface Reconstruction of C60 Epitaxial Films by Atomic Force Microscopy. Y.Kim, L.Jiang, T.Iyoda, K.Hashimoto, A.Fujishima: Surface Science, 1997, 385[2-3], L945-51