Desorption of gold nanoclusters from gold nanodispersed targets by 200 keV Au5 polyatomic ions in the elastic stopping mode: Experiment and molecular-dynamics simulation

Au nanoislet targets (∅ 2–60 nm) were bombarded by 200 keV polyatomic ions (40 keV/atom), which deposit their energy mainly in the nuclear stopping mode: ∑(dE/dx)n = 30 keV/nm and ∑(dE/dx)e = 2 keV/nm. The matter desorbed in the form of nanoclusters was registered by TEM. The total transfer of matter was determined by neutron-activation analysis. The total yield of the ejected gold reached high values of up to 2.6 × 104 atoms per Au5 ion. The major part (2 × 104 atoms per ion Au5) of the emission is in the form of nanoclusters. The results are compared with the data of similar experiments with 1 MeV Au5 (200 keV/atom) and other projectiles. The analysis of the experimental data and the comparison to molecular-dynamics simulation results of the desorption process show that the desorption of Au nanoislets is induced by their melting, build-up of pressure and thermal expansion.