IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Processing at the Nanoscale Monday Sessions
       Session PN-MoM

Paper PN-MoM3
Attractive Mode Manipulation of Fullerenes on Si(100)

Monday, October 29, 2001, 10:20 am, Room 133

Session: Atomic/Nano-scale Manipulation
Presenter: D.L. Keeling, University of Nottingham, UK
Authors: D.L. Keeling, University of Nottingham, UK
M.J. Humphry, University of Nottingham, UK
P.H. Beton, University of Nottingham, UK
P. Moriarty, University of Nottingham, UK
M.A. Phillips, University of Nottingham, UK
Correspondent: Click to Email
Room temperature STM manipulation of C60 on silicon surfaces under ultra-high vacuum has been investigated. A new intrinsic attractive mode of manipulation has been observed for gap impedances 1-3GOhm in which molecules hop towards the tip in steps of 1-3 lattice constants. These effects are observed in both polarities although a greater stability and higher probability for attractive mode manipulation is observed for negative sample bias. A similar effect can give rise to a continuous dragging of the molecule while scanning, for which the displacement is parallel to the dimer rows. For lower gap impedance, ~1GOhm, repulsive manipulation, characterised by a sawtooth response of the tip similar to that reported by Bartels et.al., is observed in which the molecule is displaced across the surface in regular steps of 1 or 3 surface lattice constants. The response of molecules to manipulation is discussed in terms of a simple model for C60-Si(100) bonding in which two out of four Si-C bonds are broken during the manipulation process and a change in molecular orientation accompanies tip induced displacement.