Publications

Ab initio investigations of point and complex defect structures in B2-FeAl

Sözen, H.I. and Mendive-Tapia, E. and Hickel, T. and Neugebauer, J.

PHYSICAL REVIEW MATERIALS
Volume: 6 Pages:
DOI: 10.1103/PhysRevMaterials.6.023603
Published: 2022

Abstract
We study single-site and two-site defect structures in B2-type Fe-Al alloys by means of density functional theory supercell calculations. The defect formation energies are calculated as functions of the chemical potential, which are used to obtain the dependence of the defect concentrations on Al content at different temperatures. We also examine the converging behavior of the formation energies with respect to the supercell size to study the corresponding limit of dilute defects. The effect of magnetism is investigated by considering nonmagnetic, ferromagnetic, and paramagnetic states, calculations for the latter showing that the magnitude of the local magnetic moments strongly impacts the defect formation energies. The methodological studies are used to provide explanations for the wide spread of defect formation energies reported by experiments and other theoretical investigations. Based on these insights, the stability of the B2-FeAl structure as a function of Al concentration is obtained and discussed. © 2022 authors. Published by the American Physical Society.published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.

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