Phonon spectrum, thermal expansion and heat capacity of UO2 from first-principles

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27740%2F12%3A86085149" target="_blank" >RIV/61989100:27740/12:86085149 - isvavai.cz</a>

Výsledek na webu

—

DOI - Digital Object Identifier

—

Jazyk výsledku

angličtina

Název v původním jazyce

Phonon spectrum, thermal expansion and heat capacity of UO2 from first-principles

Popis výsledku v původním jazyce

We report first-principles calculations of the phonon dispersion spectrum, thermal expansion, and heat capacity of uranium dioxide. The so-called direct method, based on the quasiharmonic approximation, is used to calculate the phonon frequencies withina density functional framework for the electronic structure. The phonon dispersions calculated at the theoretical equilibrium volume agree well with experimental dispersions. The computed phonon density of states (DOSs) compare reasonably well with measured data, as do also the calculated frequencies of the Raman and infrared active modes including the LO/TO splitting. To study the pressure dependence of the phonon frequencies we calculate phonon dispersions for several lattice constants. Our computed phonon spectra demonstrate the opening of a gap between the optical and acoustic modes induced by pressure. Taking into account the phonon contribution to the total free energy of UO2 its thermal expansion coefficient and heat capacity hav

Název v anglickém jazyce

Phonon spectrum, thermal expansion and heat capacity of UO2 from first-principles

Popis výsledku anglicky

We report first-principles calculations of the phonon dispersion spectrum, thermal expansion, and heat capacity of uranium dioxide. The so-called direct method, based on the quasiharmonic approximation, is used to calculate the phonon frequencies withina density functional framework for the electronic structure. The phonon dispersions calculated at the theoretical equilibrium volume agree well with experimental dispersions. The computed phonon density of states (DOSs) compare reasonably well with measured data, as do also the calculated frequencies of the Raman and infrared active modes including the LO/TO splitting. To study the pressure dependence of the phonon frequencies we calculate phonon dispersions for several lattice constants. Our computed phonon spectra demonstrate the opening of a gap between the optical and acoustic modes induced by pressure. Taking into account the phonon contribution to the total free energy of UO2 its thermal expansion coefficient and heat capacity hav

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

—

Projekt

<a href="/cs/project/ED1.1.00%2F02.0070" target="_blank" >ED1.1.00/02.0070: Centrum excelence IT4Innovations</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2012

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

426

Číslo periodika v rámci svazku

19 March 2012

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

6

Strana od-do

109-114

Kód UT WoS článku

—

EID výsledku v databázi Scopus

—