Modifying the properties of nanoparticles by ion irradiation leads to sputtering and defect production, possibly enhanced by the high surface-to-volume ratio of the irradiated objects. By molecular-dynamics simulations, we address the size dependence of platinum nanoparticles’ response to light ion irradiation and show that in contrast to irradiation by heavier ions the sputtering yield does not depend on the particle size. In contrast, very high vacancy concentrations can be obtained in nanoparticles, the maximal concentration depending on the particle size. The evolution of vacancy concentration and sputtering upon irradiation are rationalized in terms of a kinetic model based on single knock-on events.

• Received 17 June 2009

DOI:https://doi.org/10.1103/PhysRevB.80.132101