Atomistic simulations of the formation of < c >-component dislocation
loops in alpha-zirconium
C Dai and L Balogh and ZW Yao and MR Daymond, JOURNAL OF NUCLEAR
MATERIALS, 478, 125-134 (2016).
The formation of -component dislocation loops in alpha-Zr is believed
to be responsible for the breakaway irradiation growth experimentally
observed under high irradiation fluences. However, while -loop growth
is well described by existing models, the atomic mechanisms responsible
for the nucleation of -component dislocation loops are still not
clear. In the present work, both interstitial and vacancy -type
dislocation loops are initially equilibrated at different temperatures.
Cascades simulations in the vicinity of the -type loops are then
performed by selecting an atom as the primary knock-on atoms (PKAs) with
different kinetic energies, using molecular dynamics simulations. No
-component dislocation loop was formed in cascades simulations with a
10 keV PKA, but -component interstitial loops were observed after the
interaction between discontinuous 50 keV PKAs and preexisting -type
interstitial loops. The comparisons of cascades simulations in volumes
having preexisting -type interstitial and vacancy loops suggest that
the reaction between the PKAs and -type interstitial loops is
responsible for the formation of -component interstitial loops. (C)
2016 Elsevier B.V. All rights reserved.
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