Effects of crystallographic and geometric orientation on ion beam sputtering of gold nanorods

J A Hinks,K Nordlund,D C Bufford,F Hibberd,A Kuronen,G Greaves,F Djurabekova,K Hattar,A Ilinov,S E Donnelly

doi:10.1038/s41598-017-17424-9

Abstract

Nanostructures may be exposed to irradiation during their manufacture, their engineering and whilst in-service. The consequences of such bombardment can be vastly different from those seen in the bulk. In this paper, we combine transmission electron microscopy with in situ ion irradiation with complementary computer modelling techniques to explore the physics governing the effects of 1.7 MeV Au ions on gold nanorods. Phenomena surrounding the sputtering and associated morphological changes caused by the ion irradiation have been explored. In both the experiments and the simulations, large variations in the sputter yields from individual nanorods were observed. These sputter yields have been shown to correlate with the strength of channelling directions close to the direction in which the ion beam was incident. Craters decorated by ejecta blankets were found to form due to cluster emission thus explaining the high sputter yields.

Highlights

With the continued drive to miniaturise technology and to explore the opportunities presented by nanoscience, there comes the need to understand the behaviour of nanomaterials under the various conditions potentially experienced both during manufacture and whilst in-service
We reported on enhanced sputter yields exceeding 103 atoms.ion−1 for gold nanorods irradiated with 80 keV Xe ions both observed in situ via transmission electron microscopy (TEM) and simulated using molecular dynamics[12,13]
The technique of TEM with in situ ion irradiation allows the direct observation of a sample whilst it undergoes dynamic microstructural evolution induced by the ion beam

Summary

Introduction

With the continued drive to miniaturise technology and to explore the opportunities presented by nanoscience, there comes the need to understand the behaviour of nanomaterials under the various conditions potentially experienced both during manufacture and whilst in-service. Channelling has the potential to vastly dilute the density of energy deposition and to extend the range of ions in a material; as the scale of the target is reduced, this can result in a shift of the nuclear energy deposition peak outside the dimensions of a nanostructure. In the proximity of a surface, an atomic collision cascade can cause the mass ejection of atoms via cluster emission[12,13]. Such events can result in significantly-enhanced sputter yields in nanostructures with their increased surface-area-to-volume ratios. Of sputtering and this was tentatively attributed to channelling effects dictated by the crystallographic orientations of the individual nanorods relative to the incident ion beam

Methods

Results

Conclusion