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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

Temperature and energy taken away from NP by emission. a Temperature in the irradiated NP at the end of the simulation and b energy taken away by the transmitted projectile and sputtered particles as a function of impact angle
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Fig6: Temperature and energy taken away from NP by emission. a Temperature in the irradiated NP at the end of the simulation and b energy taken away by the transmitted projectile and sputtered particles as a function of impact angle

Mentions: We determine the total amount of energy actually deposited in the NP. Figure 6a shows the final temperature in the NP as a function of the impact angle. We see that the temperature has considerably increased above the initial temperature of 300 K. The average temperature increase amounts to 189 ± 32 K; this corresponds to a retained energy in the NP of 22 keV. The energy taken away from the NP by the transmitted projectile and the sputtered particles amount to roughly 138 ± 7 keV, as Fig. 6b demonstrates. However, 40 keV has been deposited in the electronic system of the irradiated NP; it will flow back with a time scale of 98 ps [27] to the atomic system of the NP. Thus, in total, 62 keV is retained in the NP, corresponding to 31 % of the impact energy.Fig. 6


Collision-spike Sputtering of Au Nanoparticles.

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

Temperature and energy taken away from NP by emission. a Temperature in the irradiated NP at the end of the simulation and b energy taken away by the transmitted projectile and sputtered particles as a function of impact angle
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig6: Temperature and energy taken away from NP by emission. a Temperature in the irradiated NP at the end of the simulation and b energy taken away by the transmitted projectile and sputtered particles as a function of impact angle
Mentions: We determine the total amount of energy actually deposited in the NP. Figure 6a shows the final temperature in the NP as a function of the impact angle. We see that the temperature has considerably increased above the initial temperature of 300 K. The average temperature increase amounts to 189 ± 32 K; this corresponds to a retained energy in the NP of 22 keV. The energy taken away from the NP by the transmitted projectile and the sputtered particles amount to roughly 138 ± 7 keV, as Fig. 6b demonstrates. However, 40 keV has been deposited in the electronic system of the irradiated NP; it will flow back with a time scale of 98 ps [27] to the atomic system of the NP. Thus, in total, 62 keV is retained in the NP, corresponding to 31 % of the impact energy.Fig. 6

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