Formation of stable sessile interstitial complexes in reactions between glissile dislocation loops in bcc Fe
2008 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 382, no 2-3, 126-133 p.Article in journal (Refereed) Published
Clusters of self-interstitial atoms (loops) are commonly observed in the microstructure of irradiated metals. These clusters can be formed directly in high-energy displacement cascades or by growth as a result of interaction between individual self interstitials. The majority of these clusters have features of glissile dislocation loops and migrate by fast one-dimensional glide. In this paper, we present results of a systematic molecular dynamics (MD) study of reactions involving glissile interstitial loops. By the example of bcc iron we demonstrate that the reactions can produce a number of specific, stable microstructural features, with different properties compared to the reactants. Namely, the reactions between the most common glissile clusters of < 111 > crowdions can result in coarsening or formation of immobile self interstitial complexes. The coarsening leads to a decrease of the total dislocation line length and therefore is favourable. The structure and stability of the junction formed in the reactions has been studied using many body potentials and density functional theory (DFT) techniques. No evidence of the formation of a < 100 > loop from two glissile < 111 > clusters was found among the studied reactions. The immobile self interstitial complexes that form as a result of these reaction have, however, high binding energies, of the order of tens of eV, implying that a relatively long life time should be assigned to the resulting configurations and therefore that such objects are expected to contribute to the evolution of the microstructure under irradiation.
Place, publisher, year, edition, pages
2008. Vol. 382, no 2-3, 126-133 p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:kth:diva-62839DOI: 10.1016/j.jnucmat.2008.08.031ISI: 000261843900007OAI: oai:DiVA.org:kth-62839DiVA: diva2:481229
QC 20120124. Symposium on Microstructural Processes in Irradiated Materials held at the 2007 TMS Annual Meeting, Orlando, FL, FEB 25-MAR 01, 20072012-01-202012-01-202012-01-24Bibliographically approved