Year: 2024
Type: article
Abstract: We have done comprehensive first-principles calculations of He-vacancy-interstitial clusters in FCC nickel. The calculated total binding energy of Vn (Ni vacancy cluster), In (Ni interstitial cluster), Hen (helium interstitial cluster), HenV (helium interstitials in one vacancy), and HenV2 (helium interstitials in one divacancy) cluster is reported. The total binding energy of a two Ni interstitial cluster is relatively large (1.07 eV), and the binding energy between a monovacancy and a vacancy cluster containing <20 vacancies is relatively small (<0.8 eV). The dissociation/emission energy barrier of a Ni interstitial from a He3 interstitial cluster (three helium interstitial clusters) and a He8V cluster (eight helium interstitials in one vacancy) is ≤1.06 and ≤1.32 eV, respectively. The diffusion activation energy of helium is 1.36 eV via a dissociative mechanism. Comparisons with reported experimental results of helium diffusion and helium desorption have been done to verify the calculation results. The relative stability of stacking fault tetrahedron and void has been investigated further based on quasi-harmonic phonon calculations directly to consider the temperature effects. The reported binding energy results can be used to build molecular simulation potentials or provide input parameters for the cluster dynamics or lattice Monte Carlo simulations of helium-defect cluster evolution.
Source: Journal of Applied Physics
DOI: 10.1063/5.0220349
Institutions: Sichuan University, Shenzhen University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,500
Funder: Sichuan University
Award: G4050086079
OpenAlex ID: W4402684537