Morphology and evolution of size-selected metallic clusters deposited on a metal surface:Ag19+/Pd(100)

We study size-selected deposition of ${\mathrm{Ag}}_{19}^{+}$ clusters on Pd(100) at total kinetic energies of 20 and 95 eV using thermal energy atom scattering and molecular-dynamics simulations. Contrary to the case of ${\mathrm{Ag}}_7$ where fragmentation is crucial to explain the data, the deposition leads at low temperature to noncompact structures localized around the impact point. We propose a model in which morphology changes take place between 200 and 300 K resulting in well-separated compact structures.