Molecular dynamics simulation of polymerlike thin films irradiated by fast ions: A comparison between FENE and Lennard-Jones potentials
Author
dc.contributor.author
Lima, N. W.
Author
dc.contributor.author
Gutierres, L. S.
Author
dc.contributor.author
González, R. I.
Author
dc.contributor.author
Mueller, S.
Author
dc.contributor.author
Thomaz, R. S.
Author
dc.contributor.author
Bringa, E. M.
Author
dc.contributor.author
Papaleo, R. M.
Admission date
dc.date.accessioned
2017-11-14T18:40:10Z
Available date
dc.date.available
2017-11-14T18:40:10Z
Publication date
dc.date.issued
2016
Cita de ítem
dc.identifier.citation
Physical Review B 94, 195417 (2016)
es_ES
Identifier
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10.1103/PhysRevB.94.195417
Identifier
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https://repositorio.uchile.cl/handle/2250/145621
Abstract
dc.description.abstract
In this paper, the surface effects of individual heavy ions impacting thin polymerlike films were investigated, using molecular dynamics simulations with the finite extensible nonlinear elastic (FENE) potential to describe the molecular chains. The perturbation introduced by the ions in the lattice was modeled assuming that the initial excitation energy in the ion track is converted into an effective temperature, as in a thermal spike. The track was heated only within the film thickness h, leaving a nonexcited substrate below. The effect of decreasing thickness on cratering and sputtering was evaluated. The results were compared to experimental data of thin polymer films bombarded by MeV-GeV ions and to simulations performed with the Lennard-Jones potential. While several qualitative results observed in the experiments were also seen in the simulations, irrespective of the potential used, there are important differences observed on FENE films. Crater dimensions, rim volume, and sputtering yields are substantially reduced, and a threshold thickness for molecular ejection appears in FENE simulations. This is attributed to the additional restrictions on mass transport out of the excited track region imposed by interchain interactions (entanglements) and by the low mobility of the molten phase induced by the spike.
es_ES
Patrocinador
dc.description.sponsorship
CNPq
CAPES (Brazil)
Fondo Nacional de Investigaciones Cientificas y Tecnologicas (FONDECYT, Chile)
3140526
Financiamiento Basal para Centros Cientificos y Tecnologicos de Excelencia
FB-0807
(ANPCyT), a SeCTyP-UN Cuyo grant
18352/R0
18686