Rights statement: This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review. To access the final edited and published work seehttps://pubs.acs.org/doi/10.1021/acs.jpcc.0c02551
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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Influence of Lithium Vacancy Defects on Tritium Diffusion in β-Li2TiO3
AU - Goswami, K.N.
AU - Murphy, S.T.
N1 - This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review. To access the final edited and published work seehttps://pubs.acs.org/doi/10.1021/acs.jpcc.0c02551
PY - 2020/6/11
Y1 - 2020/6/11
N2 - Lithium metatitanate, Li2TiO3, is a leading candidate for application as a tritium breeding material in a future fusion reactor. Following transmutation of lithium, the tritium must escape the crystal in order to be extracted for use in the fusion plasma. The rate-limiting step to release tritium from the Li2TiO3 pebbles is diffusion through the crystal grains. In this work, the activation barriers for tritium diffusion have been calculated using density functional theory. The results show that tritium can diffuse as an interstitial with a barrier of 0.52 eV. However, when a tritium ion becomes bound to a lithium vacancy defect, the energy required to either detrap the tritium from the vacancy or for the cluster to diffuse increases to >1 eV. Overall, these results suggest that the introduction of lithium vacancies due to Li burn-up may lead to an increase in tritium retention in the pebbles. Copyright © 2020 American Chemical Society.
AB - Lithium metatitanate, Li2TiO3, is a leading candidate for application as a tritium breeding material in a future fusion reactor. Following transmutation of lithium, the tritium must escape the crystal in order to be extracted for use in the fusion plasma. The rate-limiting step to release tritium from the Li2TiO3 pebbles is diffusion through the crystal grains. In this work, the activation barriers for tritium diffusion have been calculated using density functional theory. The results show that tritium can diffuse as an interstitial with a barrier of 0.52 eV. However, when a tritium ion becomes bound to a lithium vacancy defect, the energy required to either detrap the tritium from the vacancy or for the cluster to diffuse increases to >1 eV. Overall, these results suggest that the introduction of lithium vacancies due to Li burn-up may lead to an increase in tritium retention in the pebbles. Copyright © 2020 American Chemical Society.
KW - Crystals
KW - Density functional theory
KW - Diffusion
KW - Titanium compounds
KW - Tritium
KW - Activation barriers
KW - Burn up
KW - Crystal grains
KW - Fusion plasmas
KW - Lithium vacancy
KW - Rate-limiting steps
KW - Tritium breeding materials
KW - Tritium retention
KW - Lithium compounds
U2 - 10.1021/acs.jpcc.0c02551
DO - 10.1021/acs.jpcc.0c02551
M3 - Journal article
VL - 124
SP - 12286
EP - 12294
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 23
ER -