Atomistic study of magnetism effect on structural stability in Fe3Al and Fe3AlX (X = H, B, C, N, O) alloys

Atomistic modeling based on the density-functional theory (DFT) within the generalized-gradient approximation (GGA) is used to study the magnetic properties Fe3Al and FC3AlX (X = H, B, C, N, O) compounds. The phase stability and the structural parameters are calculated for the selected iron-aluminide alloys. The magnetic effects in Fe3AlX are shown and the predicted properties agree very well with the available experimental data. In the case of Fe3Al alloy, the DO3 structure is found to be more favorable than the Ll(2) one. To the authors' knowledge, this is the first time that spin-polarized GGA calculations have given the correct ground state of the Fe3Al alloys. In addition, the hypothetical phase of Fe3AlX' (X' = H, B, N, and O) structure is compared to the experimentally observed Fe3AlC structure. The unusual effect on magnetic properties of the C addition is shown. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.