STRUCTURAL DETERMINATION OF THE C-60 GE(111) INTERFACE VIA X-RAY-DIFFRACTION/

An X-ray diffraction study was performed to determine the nature of th e 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) period icity at the C-60/Ge(111) interface with no trace of the c(2 x 8) reco nstruction, indicating that the Ce adatoms on the clean c(2 x 8)-recon structed surface are displaced. Scans alone the (10) rod indicate that these adatoms are transferred from the T-4 bonding site to the H-3 si te after C-60 deposition. A model consisting of three relaxed bilayers of Ge and randomly distributed adatoms in the H-3 site explains our r esults. (C) 1998 Elsevier Science B.V.