Fast three dimensional migration of He clusters in bcc Fe and Fe-Cr alloys
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Fast three dimensional migration of He clusters in bcc Fe and Fe-Cr alloys. / Terentyev, Dmitry; Juslin, N.; Nordlund, Kai; Sandberg, Nils; Lucon, Enrico (Peer reviewer).
In: Journal of Applied Physics, Vol. 105, No. 10, 15.05.2009, p. 103509-103509.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Fast three dimensional migration of He clusters in bcc Fe and Fe-Cr alloys
AU - Terentyev, Dmitry
AU - Juslin, N.
AU - Nordlund, Kai
AU - Sandberg, Nils
A2 - Lucon, Enrico
N1 - Score = 10
PY - 2009/5/15
Y1 - 2009/5/15
N2 - In this work, we perform atomistic molecular dynamics simulations to assess the properties of small helium vacancy (He-V) and pure He clusters in body-centered cubic Fe and in Fe-90-Cr-10 (Fe-10Cr) random alloy. The following two goals are pursued: determining diffusion mechanisms of He-V clusters occurring in dynamic simulations and revealing a possible influence of Cr on the mobility/stability of He-V clusters in the Fe-10Cr alloy. We also present a newly developed set of interatomic potentials for the Fe-Cr-He system, fitted to a set of specially performed density functional theory calculations. The obtained results show that the dissociation energies of the studied He-V clusters, as well as the migration energy of He interstitial, are not significantly affected in the alloy compared to pure Fe. It was found that small pure He clusters with sizes up to four atoms, that were assumed to be immobile in many previous studies devoted to He-release/accumulation kinetics, in fact, exhibit fast three dimensional motion with a migration energy of tens of meV. The presence of 10% Cr in the Fe matrix, however, retards their mobility. We discuss possible reasons for the decreased diffusivity of these He clusters in the Fe-Cr alloy.
AB - In this work, we perform atomistic molecular dynamics simulations to assess the properties of small helium vacancy (He-V) and pure He clusters in body-centered cubic Fe and in Fe-90-Cr-10 (Fe-10Cr) random alloy. The following two goals are pursued: determining diffusion mechanisms of He-V clusters occurring in dynamic simulations and revealing a possible influence of Cr on the mobility/stability of He-V clusters in the Fe-10Cr alloy. We also present a newly developed set of interatomic potentials for the Fe-Cr-He system, fitted to a set of specially performed density functional theory calculations. The obtained results show that the dissociation energies of the studied He-V clusters, as well as the migration energy of He interstitial, are not significantly affected in the alloy compared to pure Fe. It was found that small pure He clusters with sizes up to four atoms, that were assumed to be immobile in many previous studies devoted to He-release/accumulation kinetics, in fact, exhibit fast three dimensional motion with a migration energy of tens of meV. The presence of 10% Cr in the Fe matrix, however, retards their mobility. We discuss possible reasons for the decreased diffusivity of these He clusters in the Fe-Cr alloy.
KW - chromium alloys
KW - density functional theory
KW - diffusion
KW - dissociation energies
KW - helium
KW - iron
KW - iron alloys
KW - molecular dynamics method
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_100841
UR - http://knowledgecentre.sckcen.be/so2/bibref/6186
U2 - 10.1063/1.3126709
DO - 10.1063/1.3126709
M3 - Article
VL - 105
SP - 103509
EP - 103509
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 10
ER -
ID: 128251