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Behaviors of transmutation elements Re and Os and their effects on energetics and clustering of vacancy and self-interstitial atoms in W.
- Source :
-
Nuclear Fusion . Apr2017, Vol. 57 Issue 4, p1-1. 1p. - Publication Year :
- 2017
-
Abstract
- We investigate the behaviors of rhenium (Re) and osmium (Os) and their interactions with point defects in tungsten (W) using a first-principles method. We show that Re atoms are energetically favorable to disperse separately in bulk W due to the Re–Re repulsive interaction. Despite the attractive interaction between Os atoms, there is still a large activation energy barrier of 1.10 eV at the critical number of 10 for the formation of Os clusters in bulk W based on the results of the total nucleation free energy change. Interestingly, the presence of vacancy can significantly reduce the total nucleation free energy change of Re/Os clusters, suggesting that vacancy can facilitate the nucleation of Re/Os in W. Re/Os in turn has an effect on the stability of the vacancy clusters (Vn) in W, especially for small vacancy clusters. A single Re/Os atom can raise the total binding energies of V2 and V3 obviously, thus enhancing their formation. Further, we demonstrate that there is a strong attractive interaction between Re/Os and self-interstitial atoms (SIAs). Re/Os could increase the diffusion barrier of SIAs and decrease their rotation barrier, while the interstitial-mediated path may be the optimal diffusion path of Re/Os in W. Consequently, the synergistic effect between Re/Os and point defects plays a key role in Re/Os precipitation and the evolution of defects in irradiated W. [ABSTRACT FROM AUTHOR]
- Subjects :
- *NUCLEAR reactions
*POINT defects
*TUNGSTEN
*NUCLEATION
*OSMIUM
*RHENIUM
Subjects
Details
- Language :
- English
- ISSN :
- 00295515
- Volume :
- 57
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Nuclear Fusion
- Publication Type :
- Academic Journal
- Accession number :
- 121758449
- Full Text :
- https://doi.org/10.1088/1741-4326/aa5893