MECHANISM FOR DIFFUSION OF NANOSTRUCTURES AND MESOSCOPIC OBJECTS ON SURFACES

We have studied the diffusion of mesoscopic objects created on surfaces by applying time rescaling Monte Carlo algorithms. It is shown that under the effect of very small forces (0.01-0.03 eV/lattice constant), these nanostructures reach large velocities and long displacements are observable. The main mechanism involved in this displacement is the fast movement of the particles at the cluster perimeter, i.e. at an adequate temperature, for instance Au at room temperature, Au atoms move very fast along the cluster periphery and the application of a small driving force gives rise to the displacement of the object as a whole. Atomic metallic ion emission (AMIE) experiments are presented and explained in terms of our MC results.