Nanoscale Patterning by C60 Ordering on Pt(110)
Résumé
Grazing incidence X-ray diffraction was used to determine the structure of one monolayer of C60 on Pt(110)- (1×2) surface. The data reveal that a c(4×4) reconstruction was induced by fullerene on Pt with the creation of a regular array of nanopits. The partial refilling of the initial (1×2) missing row by Pt atoms involves long-range mass transport ending up with a 75% Pt occupancy of the topmost surface layer. The orientation of the molecule is compatible with cm local surface symmetry, with one of the C60 pentagons facing the surface and two adjacent hexagonal rings almost parallel to the (111) facets formed by the nanopit. The increase of the van der Waals repulsion forces induced by the short nearest neighbor C60 distances (9.6 Å) is compensated by the formation of 15 C-Pt bonds with lengths ranging from 2.1 and 2.6 Å that could be responsible for a charge transfer between the substrate and the molecule through a large contact area and a reduction of 6% of the C60 diameter. Extensive comparison of our model derived from experimental X-ray data with other models published in literature was carried out.