Dynamics of nanostructures
Diffusion and ripening of nanoclusters consisting of ten to some hundreds atoms was investigated on surfaces of different symmetry (Ag(111) and Ag(110). This study allowed to determine the underlying atomistic processes and their energy barriers. The studies were recently extended to heteroepitaxial systems, e.g. Cu/Ag(111), Co/Au(111) and Cu/Ag(100). The lattice mismatch causes a substantially different behavior below a certain critical cluster size. The lattice mismatch likewise influence the diffusion barriers of single adatoms and dimers and the rotational barrier of the dimers. These model studies lead to a fundamental understanding of ripening phenomena on metal surfaces
Further measurements for adsorbates with a larger size than the substrate lattice and studies for sizes in between dimers and nanoclusters are planned.
Currently, we investigate diffusion and ripening of metallorganic molecule clusters expecting an influence onto the dynamic behavior based on the more specific interactions in between the particles as compared to the isotropic interaction of atoms. This topic sheds light on the fundamental interactions between adsorbed particles and is thus of fundamental importance for growth, structure formation and self-organization.