Desorption of nanoclusters from gold nanodispersed layers by 72keV Au400 ions: Experiment and molecular dynamics simulation

News on sputter theory: Molecular targets, nanoparticle desorption, rough surfaces

“…In addition to cluster emission during sputtering, in some specific experiments the emission of nanoparticles, which had been adsorbed to the surface of a substrate prior to bombardment, has been reported. In a series of experiments, Baranov and coworkers found that such emission occurs for a wide range of impact conditions; the most recent references include [17][18][19][20][21]. These authors investigated energy deposition by the projectile both in the nuclear stopping regime -for instance, impact of 72 keV Au 400 clusters or 200 keV Au 5 clusters -and in the electronic stopping regime, such as 1 GeV Pb ions or 30 MeV C 60 clusters.…”

“…momentum may desorb the nanoparticle from the surface. This mechanism has been investigated quantitatively using molecular dynamics simulation [20] and an efficiency of around 10% for desorption has been found for the special case investigated. Emission is most effective in a small window of impact parameters: If the nanoparticle is hit centrally, it may be destroyed; if it is hit too far at the periphery, or not at all, it will remain sticking to the surface.…”

Synergism in sputtering of copper nanoclusters on graphite substrate at low energy Cu2 bombardment

“…It is seen that at large bombarding energies the inverse square law fits nicely the high-energy tail of the energy spectrum of sputtered atoms. For Cu 13 and Cu 195 clusters, the low energy maximum of sputtering intensity is located at 1.0-1.5 and 2.0-2.5 eV respectively (Fig. 3).…”

“…3). The increase of energy is connected with the fact that the surface binding energy of atoms in a cluster increases with its size (2.57 and 3.08 eV for Cu 13 and Cu 195 clusters, respectively [21]). This binding effect is qualitatively similar to that for the Thompson-Sigmund energy spectrum of atoms sputtered from a flat surface in the case of planar surface potential [15].…”

“…Some attention was paid to desorption of surface nanoclusters and large molecules [13] and to sputtering of big clusters located on a solid surface and consisting of thousands of atoms [14]. At the same time many questions of fragmentation of surface nanoobjects due to atomic particle irradiation are still open.…”