Effect of carbon vacancies and oxygen impurities on the dynamical and thermal properties of uranium monocarbide

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F21%3A10425288" target="_blank" >RIV/00216208:11320/21:10425288 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61989100:27640/21:10246146 RIV/61989100:27740/21:10246146

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=3aDMlnM8Fu" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=3aDMlnM8Fu</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jnucmat.2020.152547" target="_blank" >10.1016/j.jnucmat.2020.152547</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of carbon vacancies and oxygen impurities on the dynamical and thermal properties of uranium monocarbide

Popis výsledku v původním jazyce

An influence of carbon vacancies and substitutional oxygen impurities on the phonon dynamics and thermal properties of uranium monocarbide is investigated within the density functional theory incorporating strong local Coulomb and spin-orbit interactions. Anharmonicity of lattice vibrations is taken into account via the quasi-harmonic theory. Results obtained for the modeled UC1-x and UC1-xOx compositions with x = 3% show that the changes in atomic displacements and force constants induced by mono-vacancies and substitutional oxygen impurities in the carbon sublattice of UC remain restricted to the immediate neighborhood of the incorporated defects. The most sensitive to point defects in the carbon sublattice of UC are the optical phonon branches, while the phonon densities of states and the phonon-dependent thermodynamical properties remain affected to a lesser extent. The X-ray powder diffraction experiments have been performed to examine the temperature evolution of the lattice parameter of highly stoichiometric UC between 20 and 310 K. The present experimental studies supplement existing literature data by extending description of the uranium monocarbide structure below room temperature. They also support and validate our theoretical predictions about behavior of the investigated system at low temperatures. (C) 2020 Elsevier B.V. All rights reserved.

Název v anglickém jazyce

Effect of carbon vacancies and oxygen impurities on the dynamical and thermal properties of uranium monocarbide

Popis výsledku anglicky

An influence of carbon vacancies and substitutional oxygen impurities on the phonon dynamics and thermal properties of uranium monocarbide is investigated within the density functional theory incorporating strong local Coulomb and spin-orbit interactions. Anharmonicity of lattice vibrations is taken into account via the quasi-harmonic theory. Results obtained for the modeled UC1-x and UC1-xOx compositions with x = 3% show that the changes in atomic displacements and force constants induced by mono-vacancies and substitutional oxygen impurities in the carbon sublattice of UC remain restricted to the immediate neighborhood of the incorporated defects. The most sensitive to point defects in the carbon sublattice of UC are the optical phonon branches, while the phonon densities of states and the phonon-dependent thermodynamical properties remain affected to a lesser extent. The X-ray powder diffraction experiments have been performed to examine the temperature evolution of the lattice parameter of highly stoichiometric UC between 20 and 310 K. The present experimental studies supplement existing literature data by extending description of the uranium monocarbide structure below room temperature. They also support and validate our theoretical predictions about behavior of the investigated system at low temperatures. (C) 2020 Elsevier B.V. All rights reserved.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/EF16_013%2F0001791" target="_blank" >EF16_013/0001791: IT4Innovations národní superpočítačové centrum - cesta k exascale</a><br>

Návaznosti

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Nuclear Materials

ISSN

0022-3115

e-ISSN

—

Svazek periodika

545

Číslo periodika v rámci svazku

březen

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

8

Strana od-do

152547

Kód UT WoS článku

000608779900003

EID výsledku v databázi Scopus

2-s2.0-85095842866