He, Kr and Xe diffusion in ZrN: An atomic scale study
2013 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 438, no 1/3, 7-14 p.Article in journal (Refereed) Published
The atomic scale diffusion mechanisms for He, Kr and Xe in the nitride fuel component ZrN are developed from first principles. The vacancy formation energies reveal a prevalent N vacancy concentration in the material. However, a high N self-diffusion barrier hinders vacancy-aided Kr and Xe diffusion. High, attractive binding energies of interstitial Xe and Kr to a N vacancy effectively eliminate interstitial diffusion mechanism for these gases. In comparison, He exhibits considerable degrees of freedom, as it is weekly bound to a N vacancy, enhances N-vacancy aided diffusion, has the lowest interstitial migration barrier, and has the capacity to be reintroduced into the ZrN lattice as an interstitial. N self-diffusion barriers are lowered if the diffusing N is in close proximity to a substitutional atom. The obtained results suggest a high release of He, while the majority of Kr and Xe is retained, in agreement with experiments.
Place, publisher, year, edition, pages
2013. Vol. 438, no 1/3, 7-14 p.
IdentifiersURN: urn:nbn:se:kth:diva-123529DOI: 10.1016/j.jnucmat.2013.02.077ISI: 000319481700002ScopusID: 2-s2.0-84875751907OAI: oai:DiVA.org:kth-123529DiVA: diva2:627109
FunderSwedish Research Council
QC 201306112013-06-112013-06-112013-07-05Bibliographically approved