Structural determination of the C60/Ge(111) interface via X-ray diffraction

An X-ray diffraction study was performed to determine the nature of the C-60/Ge(111) interface formed by depositing C-60 on a Ge(111)-c(2 x 8) surface at room temperature. In-plane k-scans show a (1 x 1) periodicity at the C-60/Ge(111) interface with no trace of the c(2 x 8) reconstruction, indicating that the Ce adatoms on the clean c(2 x 8)-reconstructed surface are displaced. Scans alone the (10) rod indicate that these adatoms are transferred from the T-4 bonding site to the H-3 site after C-60 deposition. A model consisting of three relaxed bilayers of Ge and randomly distributed adatoms in the H-3 site explains our results. (C) 1998 Elsevier Science B.V.