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...

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Autores principales:	K. A. Nekrasov, A. E. Galashev, D. D. Seitov, S. K. Gupta
Formato:	article
Lenguaje:	EN RU
Publicado:	Uralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina 2021
Materias:	uranium dioxide hypostoichiometry oxygen diffusion nanocrystals Chemistry QD1-999
Acceso en línea:	https://doaj.org/article/ebbc3beb9d644a72ac5ca56dad88e735
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spelling	oai:doaj.org-article:ebbc3beb9d644a72ac5ca56dad88e7352021-12-01T05:53:11ZDiffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation2411-141410.15826/chimtech.2021.8.1.07https://doaj.org/article/ebbc3beb9d644a72ac5ca56dad88e7352021-03-01T00:00:00Zhttps://journals.urfu.ru/index.php/chimtech/article/view/4960https://doaj.org/toc/2411-1414A 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.K. A. NekrasovA. E. GalashevD. D. SeitovS. K. GuptaUralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina articleuranium dioxidehypostoichiometryoxygen diffusionnanocrystalsChemistryQD1-999ENRUChimica Techno Acta, Vol 8, Iss 1 (2021)
institution	DOAJ
collection	DOAJ
language	EN RU
topic	uranium dioxide hypostoichiometry oxygen diffusion nanocrystals Chemistry QD1-999
spellingShingle	uranium dioxide hypostoichiometry oxygen diffusion nanocrystals Chemistry QD1-999 K. A. Nekrasov A. E. Galashev D. D. Seitov S. K. Gupta Diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. A molecular dynamics simulation
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
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
title	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_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_sort	diffusion of oxygen in hypostoichiometric uranium dioxide nanocrystals. a molecular dynamics simulation
publisher	Uralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina
publishDate	2021
url	https://doaj.org/article/ebbc3beb9d644a72ac5ca56dad88e735
work_keys_str_mv	AT kanekrasov diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation AT aegalashev diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation AT ddseitov diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation AT skgupta diffusionofoxygeninhypostoichiometricuraniumdioxidenanocrystalsamoleculardynamicssimulation
_version_	1718405512449490944

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

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