Thermophysical properties and oxygen transport in (Thx,Pu1-x)O2
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Accepted version
Published version
Author(s)
Galvin, C
Cooper, MWD
Rushton, MJD
Grimes, RW
Type
Journal Article
Abstract
Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Thx,Pu1−x)O2
(0 ≤ x ≤ 1) between 300-3500 K. In particular, the superionic transition is investigated and viewed via the thermal dependence
of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity
and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain
compositions of (Thx,Pu1−x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also
examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen
diffusivity for (Thx,Pu1−x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1−x)O2 than PuO2
and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder.
(0 ≤ x ≤ 1) between 300-3500 K. In particular, the superionic transition is investigated and viewed via the thermal dependence
of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity
and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain
compositions of (Thx,Pu1−x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also
examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen
diffusivity for (Thx,Pu1−x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1−x)O2 than PuO2
and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder.
Date Issued
2016-10-31
Date Acceptance
2016-10-10
Citation
Scientific Reports, 2016, 6
ISSN
2045-2322
Publisher
Nature Publishing Group
Journal / Book Title
Scientific Reports
Volume
6
Copyright Statement
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
License URL
Publication Status
Published
Article Number
36024