Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation

A molecular dynamic simulation of diffusion of intrinsic oxygen anions in the bulk of hypostoichiometric UO2-x nanocrystals with a free surface was carried out. The main diffusion mechanism turned out to be the migration of oxygen by the anionic vacancies. It is shown that in the range of values of...

Full description

Saved in:
Bibliographic Details
Main Authors: K. A. Nekrasov, A. E. Galashev, D. D. Seitov, S. K. Gupta
Format: Article
Language:English
Published: Uralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina 2021-03-01
Series:Chimica Techno Acta
Subjects:
Online Access:https://chimicatechnoacta.ru/article/view/4960
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1846109611900272640
author K. A. Nekrasov
A. E. Galashev
D. D. Seitov
S. K. Gupta
author_facet K. A. Nekrasov
A. E. Galashev
D. D. Seitov
S. K. Gupta
author_sort K. A. Nekrasov
collection DOAJ
description A molecular dynamic simulation of diffusion of intrinsic oxygen anions in the bulk of hypostoichiometric UO2-x nanocrystals with a free surface was carried out. The main diffusion mechanism turned out to be the migration of oxygen by the anionic vacancies. It is shown that in the range of values of the non-stoichiometry parameter 0.05 £x £ 0.275 the oxygen diffusion coefficient D is weakly dependent on temperature, despite the uniform distribution of the vacancies over the model crystallite. The reliable D values calculated for the temperature T = 923 K are in the range from 3×10-9 to 7×10-8 cm2/s, in quantitative agreement with the experimental data. The corresponding diffusion activation energy is in the range from 0.57 eV to 0.65 eV, depending on the interaction potentials used for the calculations.
format Article
id doaj-art-ebbc3beb9d644a72ac5ca56dad88e735
institution Kabale University
issn 2411-1414
language English
publishDate 2021-03-01
publisher Uralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina
record_format Article
series Chimica Techno Acta
spelling doaj-art-ebbc3beb9d644a72ac5ca56dad88e7352024-12-25T09:36:54ZengUralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. ElʹcinaChimica Techno Acta2411-14142021-03-018110.15826/chimtech.2021.8.1.073904Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulationK. A. Nekrasov0A. E. Galashev1D. D. Seitov2S. K. Gupta3Institute of High-Temperature Electrochemistry, Yekaterinburg; Ural Federal University, YekaterinburgInstitute of High-Temperature Electrochemistry, YekaterinburgUral Federal University, YekaterinburgSt. Xavier's College, Ahmedabad, GujaratA molecular dynamic simulation of diffusion of intrinsic oxygen anions in the bulk of hypostoichiometric UO2-x nanocrystals with a free surface was carried out. The main diffusion mechanism turned out to be the migration of oxygen by the anionic vacancies. It is shown that in the range of values of the non-stoichiometry parameter 0.05 £x £ 0.275 the oxygen diffusion coefficient D is weakly dependent on temperature, despite the uniform distribution of the vacancies over the model crystallite. The reliable D values calculated for the temperature T = 923 K are in the range from 3×10-9 to 7×10-8 cm2/s, in quantitative agreement with the experimental data. The corresponding diffusion activation energy is in the range from 0.57 eV to 0.65 eV, depending on the interaction potentials used for the calculations.https://chimicatechnoacta.ru/article/view/4960uranium dioxidehypostoichiometryoxygen diffusionnanocrystals
spellingShingle K. A. Nekrasov
A. E. Galashev
D. D. Seitov
S. K. Gupta
Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation
Chimica Techno Acta
uranium dioxide
hypostoichiometry
oxygen diffusion
nanocrystals
title Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation
title_full Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation
title_fullStr Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation
title_full_unstemmed Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation
title_short Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation
title_sort diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals a molecular dynamics simulation
topic uranium dioxide
hypostoichiometry
oxygen diffusion
nanocrystals
url https://chimicatechnoacta.ru/article/view/4960
work_keys_str_mv AT kanekrasov diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation
AT aegalashev diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation
AT ddseitov diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation
AT skgupta diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation