C-60 GE(100)-(2X1) INTERFACIAL STRUCTURE

A room-temperature-deposited C-60 film on a Ge(100)-(2x1) surface reta ins the clean-surface (2x1) dimers at the interface. This is revealed by Patterson analysis of synchrotron x-ray-diffraction measurements of numerous in-plane fractional-order diffraction spots. The result sugg ests a mild interaction between the room-temperature-deposited film an d the substrate surface reconstruction. The C-60 film shows a (111) gr owth direction, and its [11(2) over bar] azimuth is oriented parallel to the {062} directions of the substrate. The result is a domain struc ture consistent with the threefold symmetry of the (111) growth direct ion and the two-domain, twofold symmetry of the substrate surface.