Carburization of the Fe3O4(111) Surface

The structures and energies of the stepwise carburized Fe tet1 - and Fe oct2 -terminated Fe 3 O 4 (111) surfaces have been computed at the level of density functional theory. Carburization of both surfaces is favored thermodynamically, and these results agree with the experimental findings. It is to note that the Fe tet1 -terminated Fe 3 O 4 (111) surface has weak coverage effects, while the Fe oct2 -terminated Fe 3 O 4 (111) surface has strong coverage effects. On the basis of the calculated free energies of equilibrium, the carburization ability shows the order of C > CH > CH 2 > CH 3 > CO.