Molecular Dynamics Study of the Energetic Impact of Ag↓(19) on Pd(100): An Interpretation of Mass-Selected Clusters Deposition Experiments

摘要

We have studied the dynamical processes and the structural modifications induced by the collision of Ag↓(19) cluster on the (100) substrate of Pd at impact energies E↓(i1) = 20 eV and E↓(i2) = 95 eV, by using embedded atom potentials. Our numerical study mimics a recent series of experimental results aiming at low-energy deposition of well-defined metallic clusters on metallic surfaces. We show that the degree of implantation and cluster fragmentation is directly related to the impact energy. A transition from a three-dimensional to a two-dimensional heterogeneous adsorbed structure is observed with increasing impact energy, in a way qualitatively consistent with the experiments. Chemical disorder in the upper substrate layers is common to both energies of deposition. This provides important indications to achieve optimal conditions for cluster deposition, leading to the controlled fabrication of adlayers having a precise chemical nature.