Trapping of He in intrinsic defects in zirconolite

Jack Mulroue; Matthew Watkins; Andrew J. Morris; Dorothy M. Duffy

doi:10.1016/j.jnucmat.2013.02.037

Trapping of He in intrinsic defects in zirconolite

Jack Mulroue, Matthew Watkins, Andrew J. Morris, Dorothy M. Duffy^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Zirconolite (CaZrTi₂O₇) is a proposed ceramic for the disposal of plutonium. Density functional theory with the dispersion correction (DFT-D3) has been used to study the behaviour of the He defect in zirconolite. The lowest energy He interstitial site is located in the 〈0 1 0〉 channels and found to have a migration barrier of 1.46 eV. There was a significant charge state dependence on the binding energies of a He atom to the vacancies, with the neutral 5-fold coordinated Ti having the strongest binding followed by the Ca vacancies. Multiple He interstitials were studied to examine if He bubbles were likely to form in bulk zirconolite. It was found that it was unfavourable for He to cluster at the concentrations studied.

Original language	English
Pages (from-to)	261-266
Number of pages	6
Journal	Journal of Nuclear Materials
Volume	437
Issue number	1-3
DOIs	https://doi.org/10.1016/j.jnucmat.2013.02.037
Publication status	Published - 2013
Externally published	Yes

ASJC Scopus subject areas

Nuclear and High Energy Physics
General Materials Science
Nuclear Energy and Engineering

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10.1016/j.jnucmat.2013.02.037

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title = "Trapping of He in intrinsic defects in zirconolite",

abstract = "Zirconolite (CaZrTi2O7) is a proposed ceramic for the disposal of plutonium. Density functional theory with the dispersion correction (DFT-D3) has been used to study the behaviour of the He defect in zirconolite. The lowest energy He interstitial site is located in the 〈0 1 0〉 channels and found to have a migration barrier of 1.46 eV. There was a significant charge state dependence on the binding energies of a He atom to the vacancies, with the neutral 5-fold coordinated Ti having the strongest binding followed by the Ca vacancies. Multiple He interstitials were studied to examine if He bubbles were likely to form in bulk zirconolite. It was found that it was unfavourable for He to cluster at the concentrations studied.",

author = "Jack Mulroue and Matthew Watkins and Morris, {Andrew J.} and Duffy, {Dorothy M.}",

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volume = "437",

pages = "261--266",

journal = "Journal of Nuclear Materials",

issn = "0022-3115",

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T1 - Trapping of He in intrinsic defects in zirconolite

AU - Mulroue, Jack

AU - Watkins, Matthew

AU - Morris, Andrew J.

AU - Duffy, Dorothy M.

PY - 2013

Y1 - 2013

N2 - Zirconolite (CaZrTi2O7) is a proposed ceramic for the disposal of plutonium. Density functional theory with the dispersion correction (DFT-D3) has been used to study the behaviour of the He defect in zirconolite. The lowest energy He interstitial site is located in the 〈0 1 0〉 channels and found to have a migration barrier of 1.46 eV. There was a significant charge state dependence on the binding energies of a He atom to the vacancies, with the neutral 5-fold coordinated Ti having the strongest binding followed by the Ca vacancies. Multiple He interstitials were studied to examine if He bubbles were likely to form in bulk zirconolite. It was found that it was unfavourable for He to cluster at the concentrations studied.

AB - Zirconolite (CaZrTi2O7) is a proposed ceramic for the disposal of plutonium. Density functional theory with the dispersion correction (DFT-D3) has been used to study the behaviour of the He defect in zirconolite. The lowest energy He interstitial site is located in the 〈0 1 0〉 channels and found to have a migration barrier of 1.46 eV. There was a significant charge state dependence on the binding energies of a He atom to the vacancies, with the neutral 5-fold coordinated Ti having the strongest binding followed by the Ca vacancies. Multiple He interstitials were studied to examine if He bubbles were likely to form in bulk zirconolite. It was found that it was unfavourable for He to cluster at the concentrations studied.

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M3 - Article

AN - SCOPUS:84875456685

SN - 0022-3115

VL - 437

SP - 261

EP - 266

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

IS - 1-3

ER -

Trapping of He in intrinsic defects in zirconolite

Abstract

ASJC Scopus subject areas

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