A pseudopotential density functional theory study of native defects and boron impurities in FeAl
2006 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 18, no 39, 8859-8876 p.Article in journal (Refereed) Published
The structures and energies of point defects and point defect complexes in B 2 iron aluminium FeAl are calculated using a local density functional theory based method with large supercells. Particular emphasis is given to pseudopotential quality, choice of chemical potentials used to calculate defect formation energies, and how these are affected by magnetism. Both purely native defects and those containing boron atoms are considered. It is found that the relative stabilities of isolated point defects versus defect complexes depends on whether the material contains excess iron or aluminium. The situation in material containing boron is further complicated by the existence of iron borides in more than one form. We propose that the interaction between point defects, dislocations, and antiphase boundaries, where the local atomic environment has some similarities with antisite defects, also depends on the alloy composition. It is likely that these interactions are part of the underlying mechanism responsible for the unusual mechanical properties of iron aluminides.
Place, publisher, year, edition, pages
2006. Vol. 18, no 39, 8859-8876 p.
density functional theory, pseudopotentials, yield stress anomaly, intermetallics, FeAl, FeB, Fe2B, Natural sciences - Physics, Materials science - Functional materials
Naturvetenskap - Fysik, Teknisk materialvetenskap - Funktionella material
Research subject Scientific Computing
IdentifiersURN: urn:nbn:se:ltu:diva-8284DOI: 10.1088/0953-8984/18/39/016Local ID: 6c64ef40-bb7a-11db-b560-000ea68e967bOAI: oai:DiVA.org:ltu-8284DiVA: diva2:981175
Validerad; 2006; 20070213 (kani)2016-09-292016-09-29Bibliographically approved