Abstract
An important challenge for modelling transport in materials for energy applications is that in most applications they are polycrystalline, and hence it is critical to understand the properties in the presence of grain boundaries. Moreover, most grain boundaries are not pristine stoichiometric interfaces and hence dopants are likely to play a significant role. In this paper, we describe our recent work on using atomistic molecular dynamics simulations to model the effect of doped grain boundaries on oxygen transport of fluorite structured UO 2. UO 2, much like other fluorite grain boundaries, are found to be sinks for oxygen vacancy segregation relative to the grain interior, thus facilitating oxygen transport. Fission products further enhance diffusivity via strong interactions between the impurities and oxygen defects. Doping produces a striking structural alteration in the Σ5 class of grain boundaries that enhances oxygen diffusivity even further. This article is part of a discussion meeting issue 'Energy materials for a low carbon future'.
| Original language | English |
|---|---|
| Article number | 20190026 |
| Pages (from-to) | 1-16 |
| Number of pages | 16 |
| Journal | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |
| Volume | 377 |
| Issue number | 2152 |
| Early online date | 8 Jul 2019 |
| DOIs | |
| Publication status | Published - 31 Aug 2019 |
Keywords
- Fission products
- MO-doped UO
- Nuclear fuel
- Oxygen diffusion
- Segregation
- Space charge in UO
ASJC Scopus subject areas
- Mathematics(all)
- Engineering(all)
- Physics and Astronomy(all)
Cite this
Defect segregation facilitates oxygen transport at fluorite UO2 grain boundaries. / Symington, A. R.; Molinari, M.; Brincat, N. A.; Williams, N. R.; Parker, S. C.
In: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 377, No. 2152, 20190026, 31.08.2019, p. 1-16.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Defect segregation facilitates oxygen transport at fluorite UO2 grain boundaries
AU - Symington, A. R.
AU - Molinari, M.
AU - Brincat, N. A.
AU - Williams, N. R.
AU - Parker, S. C.
PY - 2019/8/31
Y1 - 2019/8/31
N2 - An important challenge for modelling transport in materials for energy applications is that in most applications they are polycrystalline, and hence it is critical to understand the properties in the presence of grain boundaries. Moreover, most grain boundaries are not pristine stoichiometric interfaces and hence dopants are likely to play a significant role. In this paper, we describe our recent work on using atomistic molecular dynamics simulations to model the effect of doped grain boundaries on oxygen transport of fluorite structured UO 2. UO 2, much like other fluorite grain boundaries, are found to be sinks for oxygen vacancy segregation relative to the grain interior, thus facilitating oxygen transport. Fission products further enhance diffusivity via strong interactions between the impurities and oxygen defects. Doping produces a striking structural alteration in the Σ5 class of grain boundaries that enhances oxygen diffusivity even further. This article is part of a discussion meeting issue 'Energy materials for a low carbon future'.
AB - An important challenge for modelling transport in materials for energy applications is that in most applications they are polycrystalline, and hence it is critical to understand the properties in the presence of grain boundaries. Moreover, most grain boundaries are not pristine stoichiometric interfaces and hence dopants are likely to play a significant role. In this paper, we describe our recent work on using atomistic molecular dynamics simulations to model the effect of doped grain boundaries on oxygen transport of fluorite structured UO 2. UO 2, much like other fluorite grain boundaries, are found to be sinks for oxygen vacancy segregation relative to the grain interior, thus facilitating oxygen transport. Fission products further enhance diffusivity via strong interactions between the impurities and oxygen defects. Doping produces a striking structural alteration in the Σ5 class of grain boundaries that enhances oxygen diffusivity even further. This article is part of a discussion meeting issue 'Energy materials for a low carbon future'.
KW - Fission products
KW - MO-doped UO
KW - Nuclear fuel
KW - Oxygen diffusion
KW - Segregation
KW - Space charge in UO
UR - http://www.scopus.com/inward/record.url?scp=85068925953&partnerID=8YFLogxK
U2 - 10.1098/rsta.2019.0026
DO - 10.1098/rsta.2019.0026
M3 - Article
VL - 377
SP - 1
EP - 16
JO - Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences
JF - Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences
SN - 1364-503X
IS - 2152
M1 - 20190026
ER -