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Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm

The effect of electric fields on metal surfaces is fairly well studied, resulting in numerous analytical models developed to understand the mechanisms of ionization of surface atoms observed at very high electric fields, as well as the general behavior of a metal surface in this condition. However,...

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Autores principales: Djurabekova, Flyura, Parviainen, Stefan, Pohjonen, Aarne, Nordlund, Kai
Lenguaje:eng
Publicado: 2011
Materias:
Acceso en línea:http://cds.cern.ch/record/1354520
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author Djurabekova, Flyura
Parviainen, Stefan
Pohjonen, Aarne
Nordlund, Kai
author_facet Djurabekova, Flyura
Parviainen, Stefan
Pohjonen, Aarne
Nordlund, Kai
author_sort Djurabekova, Flyura
collection CERN
description The effect of electric fields on metal surfaces is fairly well studied, resulting in numerous analytical models developed to understand the mechanisms of ionization of surface atoms observed at very high electric fields, as well as the general behavior of a metal surface in this condition. However, the derivation of analytical models does not include explicitly the structural properties of metals, missing the link between the instantaneous effects owing to the applied field and the consequent response observed in the metal surface as a result of an extended application of an electric field. In the present work, we have developed a concurrent electrodynamic–molecular dynamic model for the dynamical simulation of an electric-field effect and subsequent modification of a metal surface in the framework of an atomistic molecular dynamics (MD) approach. The partial charge induced on the surface atoms by the electric field is assessed by applying the classical Gauss law. The electric forces acting on the partially charged surface atoms (Lorentz and Coulomb) are then introduced in the MD algorithm to correct the atomic motion in response to the applied field. The enhancement factor at sharp features on the surface for the electric field and the assessment of atomic charges are discussed. The results obtained by the present model compare well with the experimental and density-functional theory results.
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institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2011
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spelling cern-13545202023-07-20T15:03:37Zhttp://cds.cern.ch/record/1354520engDjurabekova, FlyuraParviainen, StefanPohjonen, AarneNordlund, KaiAtomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithmAccelerators and Storage RingsThe effect of electric fields on metal surfaces is fairly well studied, resulting in numerous analytical models developed to understand the mechanisms of ionization of surface atoms observed at very high electric fields, as well as the general behavior of a metal surface in this condition. However, the derivation of analytical models does not include explicitly the structural properties of metals, missing the link between the instantaneous effects owing to the applied field and the consequent response observed in the metal surface as a result of an extended application of an electric field. In the present work, we have developed a concurrent electrodynamic–molecular dynamic model for the dynamical simulation of an electric-field effect and subsequent modification of a metal surface in the framework of an atomistic molecular dynamics (MD) approach. The partial charge induced on the surface atoms by the electric field is assessed by applying the classical Gauss law. The electric forces acting on the partially charged surface atoms (Lorentz and Coulomb) are then introduced in the MD algorithm to correct the atomic motion in response to the applied field. The enhancement factor at sharp features on the surface for the electric field and the assessment of atomic charges are discussed. The results obtained by the present model compare well with the experimental and density-functional theory results.CERN-OPEN-2011-025CLIC-Note-870oai:cds.cern.ch:13545202011-02-14
spellingShingle Accelerators and Storage Rings
Djurabekova, Flyura
Parviainen, Stefan
Pohjonen, Aarne
Nordlund, Kai
Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm
title Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm
title_full Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm
title_fullStr Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm
title_full_unstemmed Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm
title_short Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm
title_sort atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm
topic Accelerators and Storage Rings
url http://cds.cern.ch/record/1354520
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AT parviainenstefan atomisticmodelingofmetalsurfacesunderelectricfieldsdirectcouplingofelectricfieldstoamoleculardynamicsalgorithm
AT pohjonenaarne atomisticmodelingofmetalsurfacesunderelectricfieldsdirectcouplingofelectricfieldstoamoleculardynamicsalgorithm
AT nordlundkai atomisticmodelingofmetalsurfacesunderelectricfieldsdirectcouplingofelectricfieldstoamoleculardynamicsalgorithm