The disappearance and return of nanoparticles upon low energy ion irradiation

Abstract

Ion irradiation of bulk and thin film materials is tightly connected to well described effects such as sputtering or/and ion beam mixing. However, when a nanoparticle is ion irradiated and the ion range is comparable to the nanoparticle size, these effects are to be reconsidered essentially. This study investigates the morphology changes of silver nanoparticles on top of silicon substrates, being irradiated with Ga+ ions in an energy range from 1 to 30 keV. The hemispherical shaped nanoparticles become conical due to an enhanced and curvature-dependent sputtering, before they finally disappear. The sputter yield and morphology changes can be well described by 3D Monte Carlo TRI3DYN simulations. However, the combination of sputtering, ion beam mixing, ion beam induced diffusion, and Ostwald ripening at ion energies lower than 8 keV results in the reappearance of new particles. These newly formed nanoparticles appear in various structures depending on the material and ion energy.

Charge‐State‐Enhanced Ion Sputtering of Metallic Gold Nanoislands

“…Recent studies on singly-charged low energy ions with nanorods and -cubes showed interesting, yet largely unexplored effects with regards to erosion and ion channeling. [18,19] In this study, we irradiate gold nanoislands grown on a MoS 2 monolayer [20,21] with single slow highly charged xenon ions. On a MoS 2 monolayer substrate the gold nanoislands are bound via van-der-Waals forces only, [21] which leads to a reduced thermal conductivity [22] and electronic coupling.…”

Ion Irradiation‐Induced Sinking of Ag Nanocubes into Substrates

“…[22][23][24][25][26] Today, being in an era of nanotechnology, the irradiated object sizes are often comparable to the projected ion range, which led to the discovery of many new effects, as the situation is different to the ion irradiation of bulk or thin films. A reduced dopant incorporation, [27] an enhanced sputtering yield [28][29][30][31][32][33][34][35] as well as an enhanced dynamic annealing and thus lower damage formation [36][37][38] are a few of those effects, which recently opened the research field of "ion-nanostructureinteractions".…”