Институт квантового материаловедения IQMS

Магнетизм и локальные искажения решетки вблизи атома углерода в γ-Fe

D. W. Boukhvalov, Yu. N. Gornostyrev, M. I. Katsnelson, A. I. Lichtenstein

Physical Review Letters PRL 99, 247205 (2007)

Local perturbations of the crystal and magnetic structure of γ-iron near carbon interstitial impurity is investigated by ab initio electronic structure calculations. It is shown that the carbon impurity creates locally a region of ferromagnetic ordering with substantial tetragonal distortions. Exchange integrals and solution enthalpy are calculated, the latter being in very good agreement with experimental data. The effect of the local distortions on the carbon-carbon interactions in γ-iron is discussed

Exchange parameters (in K) for different Fe-Fe pairs in original fcc lattice (a); in fcc lattice with carbon interstitial impurity without (b) and with (c) relaxation taken into account. Arrows indicate direction of atomic displacements during the relaxation.