Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}

Available data on the dependence of the equilibrium chemical potential of oxygen on degrees of doping, z, and non-stoichiometry, x, y, in U1-zLnzO2+0.5(x-y) fluorite solid solutions and data on the dependence of the lattice parameter, a, on the same variables are combined within a unified structural...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Victor L. Vinograd, Andrey A. Bukaemskiy, Giuseppe Modolo, Guido Deissmann, Dirk Bosbach
Formato:	article
Lenguaje:	EN
Publicado:	Frontiers Media S.A. 2021
Materias:	UO2 fluorite non-stoichiometry oxidation resistance lattice parameter thermodynamic modelling Chemistry QD1-999
Acceso en línea:	https://doaj.org/article/80e4d54b1e4049a1bc0d7dda2178157d
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:80e4d54b1e4049a1bc0d7dda2178157d
record_format	dspace
spelling	oai:doaj.org-article:80e4d54b1e4049a1bc0d7dda2178157d2021-11-16T15:54:31ZThermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}2296-264610.3389/fchem.2021.705024https://doaj.org/article/80e4d54b1e4049a1bc0d7dda2178157d2021-11-01T00:00:00Zhttps://www.frontiersin.org/articles/10.3389/fchem.2021.705024/fullhttps://doaj.org/toc/2296-2646Available data on the dependence of the equilibrium chemical potential of oxygen on degrees of doping, z, and non-stoichiometry, x, y, in U1-zLnzO2+0.5(x-y) fluorite solid solutions and data on the dependence of the lattice parameter, a, on the same variables are combined within a unified structural-thermodynamic model. The thermodynamic model fits experimental isotherms of the oxygen potential under the assumptions of a non-ideal mixing of the endmembers, UO2, UO2.5, UO1.5, LnO1.5, and Ln0.5U0.5O2, and of a significant reduction in the configurational entropy arising from short-range ordering (SRO) within cation-anion distributions. The structural model further investigates the SRO in terms of constraints on admissible values of cation coordination numbers and, building on these constraints, fits the lattice parameter as a function of z, y, and x. Linking together the thermodynamic and structural models allows predicting the lattice parameter as a function of z, T and the oxygen partial pressure. The model elucidates contrasting structural and thermodynamic changes due to the doping with LaO1.5, on the one hand, and with NdO1.5 and GdO1.5, on the other hand. An increased oxidation resistance in the case of Gd and Nd is attributed to strain effects caused by the lattice contraction due to the doping and to an increased thermodynamic cost of a further contraction required by the oxidation.Victor L. VinogradAndrey A. BukaemskiyGiuseppe ModoloGuido DeissmannDirk BosbachFrontiers Media S.A.articleUO2 fluoritenon-stoichiometryoxidation resistancelattice parameterthermodynamic modellingChemistryQD1-999ENFrontiers in Chemistry, Vol 9 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	UO2 fluorite non-stoichiometry oxidation resistance lattice parameter thermodynamic modelling Chemistry QD1-999
spellingShingle	UO2 fluorite non-stoichiometry oxidation resistance lattice parameter thermodynamic modelling Chemistry QD1-999 Victor L. Vinograd Andrey A. Bukaemskiy Giuseppe Modolo Guido Deissmann Dirk Bosbach Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}
description	Available data on the dependence of the equilibrium chemical potential of oxygen on degrees of doping, z, and non-stoichiometry, x, y, in U1-zLnzO2+0.5(x-y) fluorite solid solutions and data on the dependence of the lattice parameter, a, on the same variables are combined within a unified structural-thermodynamic model. The thermodynamic model fits experimental isotherms of the oxygen potential under the assumptions of a non-ideal mixing of the endmembers, UO2, UO2.5, UO1.5, LnO1.5, and Ln0.5U0.5O2, and of a significant reduction in the configurational entropy arising from short-range ordering (SRO) within cation-anion distributions. The structural model further investigates the SRO in terms of constraints on admissible values of cation coordination numbers and, building on these constraints, fits the lattice parameter as a function of z, y, and x. Linking together the thermodynamic and structural models allows predicting the lattice parameter as a function of z, T and the oxygen partial pressure. The model elucidates contrasting structural and thermodynamic changes due to the doping with LaO1.5, on the one hand, and with NdO1.5 and GdO1.5, on the other hand. An increased oxidation resistance in the case of Gd and Nd is attributed to strain effects caused by the lattice contraction due to the doping and to an increased thermodynamic cost of a further contraction required by the oxidation.
format	article
author	Victor L. Vinograd Andrey A. Bukaemskiy Giuseppe Modolo Guido Deissmann Dirk Bosbach
author_facet	Victor L. Vinograd Andrey A. Bukaemskiy Giuseppe Modolo Guido Deissmann Dirk Bosbach
author_sort	Victor L. Vinograd
title	Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}
title_short	Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}
title_full	Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}
title_fullStr	Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}
title_full_unstemmed	Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}
title_sort	thermodynamic and structural modelling of non-stoichiometric ln-doped uo2 solid solutions,ln = {la, pr, nd, gd}
publisher	Frontiers Media S.A.
publishDate	2021
url	https://doaj.org/article/80e4d54b1e4049a1bc0d7dda2178157d
work_keys_str_mv	AT victorlvinograd thermodynamicandstructuralmodellingofnonstoichiometriclndopeduo2solidsolutionslnlaprndgd AT andreyabukaemskiy thermodynamicandstructuralmodellingofnonstoichiometriclndopeduo2solidsolutionslnlaprndgd AT giuseppemodolo thermodynamicandstructuralmodellingofnonstoichiometriclndopeduo2solidsolutionslnlaprndgd AT guidodeissmann thermodynamicandstructuralmodellingofnonstoichiometriclndopeduo2solidsolutionslnlaprndgd AT dirkbosbach thermodynamicandstructuralmodellingofnonstoichiometriclndopeduo2solidsolutionslnlaprndgd
_version_	1718426311349764096

Thermodynamic and Structural Modelling of Non-Stoichiometric Ln-Doped UO2 Solid Solutions,Ln = {La, Pr, Nd, Gd}

Ejemplares similares