Ab initio study of formation, migration and binding properties of helium-vacancy clusters in aluminum
Ab initio calculations based on density functional theory have been performed to study the dissolution and migration of helium, and the stability of small helium-vacancy clusters HenVm (n, m=0 to 4) in aluminum. The results indicate that the octahedral configuration is more stable than the tetrahedral. Interstitial helium atoms are predicted to have attractive interactions and jump between two octahedral sites via an intermediate tetrahedral site with low migration energy of 0.10 eV. The binding energies of an interstitial He atom and an isolated vacancy to a HenVm cluster are also obtained from the calculated formation energies of the clusters. We find that the divacancy and tri--vacancy clusters are not stable, but He atoms can increase the stability of vacancy clusters. The interactions of He atoms with a vacancy are found to be in good agreement with the experimental results.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 949124
- Report Number(s):
- PNNL-SA-59526; AT6020100; TRN: US200907%%333
- Journal Information:
- Physica B Condensed Matter, 403(17):2719-2724, Vol. 403, Issue 17; ISSN 0921-4526
- Country of Publication:
- United States
- Language:
- English
Similar Records
Atomic-scale Modeling of Interactions of Helium, Vacancies and Helium-vacancy Clusters with Screw Dislocations in Alpha-Iron
First-principles study of inert gas incorporation and migration in zirconium nitride