TY - JOUR
T1 - Understanding why dislocation loops are visible in Transmission Electron Microscopy: The Tungsten Case
AU - Castin, Nicolas
AU - Bakaev, Alexander
AU - Terentyev, Dmitry
AU - Pascuet, Maria Ines
AU - Bonny, Giovanni
N1 - Score=10
PY - 2021/6/8
Y1 - 2021/6/8
N2 - Dislocation loops finely disperse in bulk W are generally visible to the transition electron microscopy (TEM) after irradiation. In the absence of strong interactions, these loops would normally diffuse very fast until being sunk at grain boundaries or at the dislocation network. In this work, we evaluate the strength of two pining effects that can explain the reason why they are nevertheless observed by TEM in bulk. On the one hand, we evaluate with density functional theory (DFT) the strength of binding between isolated loops and dissolved chemical impurities. Employing classical equations of diffusion, we estimate the resulting effective diffusion coefficient of loops. On the other hand, we consider the effect of mutual elastic interactions (MEI) between the loops, applying linear elasticity. We perform a large set of kinetic Monte Carlo (KMC) simulations, aimed at evaluating the effective diffusion coefficient, accounting for multiple interactions. Finally, we draw a map under which experimental condition (loop size and loop number density) what is the dominating pinning effect. Comparing with a large database of experimental TEM evidence, we conclude that pinning by dissolved impurities is the dominating effect.
AB - Dislocation loops finely disperse in bulk W are generally visible to the transition electron microscopy (TEM) after irradiation. In the absence of strong interactions, these loops would normally diffuse very fast until being sunk at grain boundaries or at the dislocation network. In this work, we evaluate the strength of two pining effects that can explain the reason why they are nevertheless observed by TEM in bulk. On the one hand, we evaluate with density functional theory (DFT) the strength of binding between isolated loops and dissolved chemical impurities. Employing classical equations of diffusion, we estimate the resulting effective diffusion coefficient of loops. On the other hand, we consider the effect of mutual elastic interactions (MEI) between the loops, applying linear elasticity. We perform a large set of kinetic Monte Carlo (KMC) simulations, aimed at evaluating the effective diffusion coefficient, accounting for multiple interactions. Finally, we draw a map under which experimental condition (loop size and loop number density) what is the dominating pinning effect. Comparing with a large database of experimental TEM evidence, we conclude that pinning by dissolved impurities is the dominating effect.
KW - Kinetic Monte Carlo
KW - Transition electron microscopy
KW - Radiation effects
KW - Dislocation loops
UR - https://ecm.sckcen.be/OTCS/llisapi.dll?func=ll&objId=44973648&objAction=download
U2 - 10.1016/j.jnucmat.2021.153122
DO - 10.1016/j.jnucmat.2021.153122
M3 - Article
SN - 0022-3115
VL - 555
SP - 1
EP - 9
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
M1 - 153122
ER -