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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

Snapshots of a selected impact event at 0.1 (a), 1.0 (b), 3.5 (c), 10 (d), and 100 ps (e). Ion impacts at the top at perpendicular incidence. Particles are colored according to their kinetic energy from blue (0 eV) to red (≥0.4 eV). Final sputtering yield amounts to 1164
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Fig3: Snapshots of a selected impact event at 0.1 (a), 1.0 (b), 3.5 (c), 10 (d), and 100 ps (e). Ion impacts at the top at perpendicular incidence. Particles are colored according to their kinetic energy from blue (0 eV) to red (≥0.4 eV). Final sputtering yield amounts to 1164

Mentions: Figure 3 shows the time evolution of a particular impact; in this event, the ion impact was central to the top of the NP with perpendicular impact direction. The abundant ejection starts early, at 1 ps; emission occurs both close to the impact point and at several other places at the surface of the sphere, where the projectile or fast recoils deposited their energy. Emission increases from these spots until 10 ps. At 100 ps, Fig. 3e, sputtering has ceased. Ejection occurs from isolated spots at the NP surface, both in forward and backward direction. Figure 4 shows how sputter emission is connected to energetic recoils within the NP; in this presentation, the sphere has been rendered transparent. We see how several branches of the collision cascade reach to surface spots, and particle emission has started there.Fig. 3


Collision-spike Sputtering of Au Nanoparticles.

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

Snapshots of a selected impact event at 0.1 (a), 1.0 (b), 3.5 (c), 10 (d), and 100 ps (e). Ion impacts at the top at perpendicular incidence. Particles are colored according to their kinetic energy from blue (0 eV) to red (≥0.4 eV). Final sputtering yield amounts to 1164
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig3: Snapshots of a selected impact event at 0.1 (a), 1.0 (b), 3.5 (c), 10 (d), and 100 ps (e). Ion impacts at the top at perpendicular incidence. Particles are colored according to their kinetic energy from blue (0 eV) to red (≥0.4 eV). Final sputtering yield amounts to 1164
Mentions: Figure 3 shows the time evolution of a particular impact; in this event, the ion impact was central to the top of the NP with perpendicular impact direction. The abundant ejection starts early, at 1 ps; emission occurs both close to the impact point and at several other places at the surface of the sphere, where the projectile or fast recoils deposited their energy. Emission increases from these spots until 10 ps. At 100 ps, Fig. 3e, sputtering has ceased. Ejection occurs from isolated spots at the NP surface, both in forward and backward direction. Figure 4 shows how sputter emission is connected to energetic recoils within the NP; in this presentation, the sphere has been rendered transparent. We see how several branches of the collision cascade reach to surface spots, and particle emission has started there.Fig. 3

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