The bonding of C to Fe and Ni in Fe50Ni50(L10) alloy with a stacking fault (SF) was analyzed using density functional calculations. The changes in the electronic structure of the bulk alloy upon SF introduction and after C absorption was addressed. C locates in an octahedral site with Ni atoms in its base and capped with Fe atoms. The Fe-Ni and Ni-Ni bonding decreased while the Fe-Fe bonding increased when the SF was introduced. The effect of C was to reduce the Fe-Ni and Ni-Ni overlap population up to 75% of its original value, while the Fe-Fe overlap population changed by only 3.6%. Both Fe and Ni bond to C atom at a distance of 1.80Å, which was close to that in Fe and Ni carbides metallic, clusters or C as a impurity at grain boundaries or dislocations.

The Effect of Carbon on the Electronic Structure of FeNi Alloys with a Stacking Fault. P.Jasen, E.González, G.González, L.Moro, A.Juan: Physica Status Solidi B, 2008, 245[12], 2771-8