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Helium Droplet-Mediated Deposition and Aggregation of Nanoscale Silver Clusters on Carbon Surfaces
Abstract : We present experiments and calculations of the deposition and
aggregation of silver clusters embedded in helium droplets onto an amorphous
carbon surface at room temperature. Calculations were also performed for
deposition onto a graphene surface. They involve potentials for the interaction of
carbon atoms with silver and helium atoms, provided by ab initio calculations. The
numerical simulations were performed for few-nanometer-sized silver clusters
including up to 5000 Ag atoms and He droplets with up to 105 4He atoms. The
fluid nature of the 4He droplet is accounted for by the renormalization of the He−
He interaction potential. The numerical results are consistent with deposition
experiments with an average number of 3000 Ag atoms per 4He droplet and
indicate that the aggregation of the silver clusters on the carbon surface is
mediated by secondary droplet impacts. They also reveal nontrivial dynamics of
the Ag clusters within the carrier droplet, showing a tendency to drift toward the
droplet surface. These findings are of relevance in understanding the
heterogeneous deposition patterns (large ramified islands) developed for very large droplets with an average number of Ag
atoms per droplet within the million range. Finally, the simulations of large (5000 atoms) Ag cluster deposition on graphene
reveals strong superdiffusive behavior. In stark contrast, the diffusion is negligible on the amorphous carbon surface.
https://hal-upec-upem.archives-ouvertes.fr/hal-01693358
Contributor : Alexander Mitrushchenkov <>
Submitted on : Friday, January 26, 2018 - 10:56:10 AM
Last modification on : Friday, June 19, 2020 - 7:52:04 PM
Contributor : Alexander Mitrushchenkov <>
Submitted on : Friday, January 26, 2018 - 10:56:10 AM
Last modification on : Friday, June 19, 2020 - 7:52:04 PM
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