Monovacancy-hydrogen interaction in pure aluminum: Experimental and ab-initio theoretical positron annihilation study

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F23%3A10475224" target="_blank" >RIV/00216208:11320/23:10475224 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ZrJV9M.GAq" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ZrJV9M.GAq</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.actamat.2023.118770" target="_blank" >10.1016/j.actamat.2023.118770</a>

Result language

angličtina

Original language name

Monovacancy-hydrogen interaction in pure aluminum: Experimental and ab-initio theoretical positron annihilation study

Original language description

We report here on hydrogen-vacancy interactions in high purity aluminum by employing positron annihilation spectroscopy (PAS) analysis of hydrogen-loaded samples, aiming to study the mobility of vacancies. The samples were heat treated at 893 K in an atmosphere consisting of a mixture of H2 and Ar gas and, thus, loaded with hydrogen. The samples were then quenched to ice water and subsequently measured in-situ at different tem-peratures. In parallel we performed ab-initio density functional theory (DFT) calculations of lifetimes of positrons trapped in vacancies associated with 1-8 H atoms. Our experimental results suggest in comparison with the ab-initio calculations that complexes of vacancies with one hydrogen atom (V-H pairs) were formed in Al samples annealed in a mixture of H2 and Ar gas. Furthermore, hydrogen absorbed in aluminum immobilizes vacancies, i. e. the recovery of vacancies is delayed from 220 K up to around 280 K. At that temperature, V-H complexes start to dissociate, and hydrogen atoms previously bound to vacancies are released. In contrast, for Al samples not loaded with hydrogen isolated monovacancies become mobile around 220 K. In both cases mobile vacancies start to form vacancy clusters. From our experimental data we determined that the formation energy of mono-vacancies in Al is 0.62 +/- 0.01 eV. This value is in very good agreement with 0.63 eV obtained by our ab-initio DFT calculations.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

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

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

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

Name of the periodical

Acta Materialia

ISSN

1359-6454

e-ISSN

1873-2453

Volume of the periodical

248

Issue of the periodical within the volume

15 April 2023

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

118770

UT code for WoS article

000995002900001

EID of the result in the Scopus database

2-s2.0-85149057399