Publications Details
An atomic view of cluster diffusion on metal surfaces
Field ion microscopy show a strong correlation between mobility and shape of small clusters on fcc(100) metal surfaces. For self-diffusion on Rh(100) this correlation lead to an oscillatory behavior in the activation energy of surface diffusion as a function of cluster size. Comparison of measured activation energies to theory indicate that the mechanism of cluster diffusion involves individual displacements of edge atoms (ie, perimeter diffusion). Rate-determining step in migration of clusters is partial detachment of one of the perimeter atoms. Relative ease of adatom motion along straight edges of stationary clusters also permits measurements of diffusion barriers at steps, which can be useful in interpretation of fractal vs compact island growth on fcc metal surfaces.