An attempt was made to construct an n-body potential for Fe-Cr alloys by combining the Finnis-Sinclair potentials for Fe and Cr while applying the Ackland-Vitok rules for the electron density, and the Johnson rule for the pair term, and adjusting the heat of solution of the Fe-Cr alloy and the size-factor of a Cr atom in an Fe matrix so as to fit experimental data. The resultant potential was used to study defect structures such as a vacancy-Cr complex. The estimated bonding energy of this complex was 0.026eV, and this low value was not inconsistent with experimental data; which had shown it to be less than 0.105eV. The vacancy migration temperature was about 200K for both pure Fe and for Fe-Cr alloys. Calculations were carried out for various types of interstitial-Cr complex, but the mixed dumb-bell type complex was not the most stable structure. Instead, this was a structure in which the Cr atom sat beside the <111> Fe crowdion. The binding energy for that structure was 0.12eV.

Determination of N-Body Potential for Fe-Cr Alloy System and its Application to Defect Study. T.Konishi, K.Ohsawa, H.Abe, E.Kuramoto: Computational Materials Science, 1999, 14[1-4], 108-13