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Collision-spike Sputtering of Au Nanoparticles.

Sandoval L, Urbassek HM - Nanoscale Res Lett (2015)

Bottom Line: While this feature is reasonably well understood for collision-cascade sputtering, we explore it in the regime of collision-spike sputtering using molecular-dynamics simulation.For the particular case of 200-keV Xe bombardment of Au particles, we show that collision spikes lead to abundant sputtering with an average yield of 397 ± 121 atoms compared to only 116 ± 48 atoms for a bulk Au target.The sputter yield of supported nanoparticles is estimated to be around 80 % of that of free nanoparticles due to the suppression of forward sputtering.

View Article: PubMed Central - PubMed

Affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA.

ABSTRACT
Ion irradiation of nanoparticles leads to enhanced sputter yields if the nanoparticle size is of the order of the ion penetration depth. While this feature is reasonably well understood for collision-cascade sputtering, we explore it in the regime of collision-spike sputtering using molecular-dynamics simulation. For the particular case of 200-keV Xe bombardment of Au particles, we show that collision spikes lead to abundant sputtering with an average yield of 397 ± 121 atoms compared to only 116 ± 48 atoms for a bulk Au target. Only around 31 % of the impact energy remains in the nanoparticles after impact; the remainder is transported away by the transmitted projectile and the ejecta. The sputter yield of supported nanoparticles is estimated to be around 80 % of that of free nanoparticles due to the suppression of forward sputtering.

No MeSH data available.


Related in: MedlinePlus

Sketch of the simulation setup. The Au spherical NP consists of 463,878 atoms and has a diameter of 24.8 nm. The 200-keV Xe projectile hits the surface at an angle of θ to the local surface normal on a local (111) facet. Sputtered atoms reach a damping zone as soon as they are a distance of 18 nm away from the original cluster surface
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Fig1: Sketch of the simulation setup. The Au spherical NP consists of 463,878 atoms and has a diameter of 24.8 nm. The 200-keV Xe projectile hits the surface at an angle of θ to the local surface normal on a local (111) facet. Sputtered atoms reach a damping zone as soon as they are a distance of 18 nm away from the original cluster surface

Mentions: In order to increase the efficiency of the parallelized code, we defined an external shell which slowly stops the ejecta by means of a drag term in the dynamics (see Fig. 1). The magnitude of the drag term and the thickness of the corresponding drag region are chosen in such a way that the sputtered clusters are kept apart of each other.Fig. 1


Collision-spike Sputtering of Au Nanoparticles.

Sandoval L, Urbassek HM - Nanoscale Res Lett (2015)

Sketch of the simulation setup. The Au spherical NP consists of 463,878 atoms and has a diameter of 24.8 nm. The 200-keV Xe projectile hits the surface at an angle of θ to the local surface normal on a local (111) facet. Sputtered atoms reach a damping zone as soon as they are a distance of 18 nm away from the original cluster surface
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526510&req=5

Fig1: Sketch of the simulation setup. The Au spherical NP consists of 463,878 atoms and has a diameter of 24.8 nm. The 200-keV Xe projectile hits the surface at an angle of θ to the local surface normal on a local (111) facet. Sputtered atoms reach a damping zone as soon as they are a distance of 18 nm away from the original cluster surface
Mentions: In order to increase the efficiency of the parallelized code, we defined an external shell which slowly stops the ejecta by means of a drag term in the dynamics (see Fig. 1). The magnitude of the drag term and the thickness of the corresponding drag region are chosen in such a way that the sputtered clusters are kept apart of each other.Fig. 1

Bottom Line: While this feature is reasonably well understood for collision-cascade sputtering, we explore it in the regime of collision-spike sputtering using molecular-dynamics simulation.For the particular case of 200-keV Xe bombardment of Au particles, we show that collision spikes lead to abundant sputtering with an average yield of 397 ± 121 atoms compared to only 116 ± 48 atoms for a bulk Au target.The sputter yield of supported nanoparticles is estimated to be around 80 % of that of free nanoparticles due to the suppression of forward sputtering.

View Article: PubMed Central - PubMed

Affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA.

ABSTRACT
Ion irradiation of nanoparticles leads to enhanced sputter yields if the nanoparticle size is of the order of the ion penetration depth. While this feature is reasonably well understood for collision-cascade sputtering, we explore it in the regime of collision-spike sputtering using molecular-dynamics simulation. For the particular case of 200-keV Xe bombardment of Au particles, we show that collision spikes lead to abundant sputtering with an average yield of 397 ± 121 atoms compared to only 116 ± 48 atoms for a bulk Au target. Only around 31 % of the impact energy remains in the nanoparticles after impact; the remainder is transported away by the transmitted projectile and the ejecta. The sputter yield of supported nanoparticles is estimated to be around 80 % of that of free nanoparticles due to the suppression of forward sputtering.

No MeSH data available.


Related in: MedlinePlus