Electronic and magnetic properties of the Fe3Si(001) surface

We investigated the electronic structure and magnetism of the bulk and the (001) surface of the magnetic silicide Fe3Si (having the same crystal structure as Heusler alloys X(2)YZ) by using the full potential linearized augmented plane wave (FLAPW) method based on the generalized gradient approximation. For the surface calculations, two ideal FeSi-terminated and Fe-terminated surfaces were taken into account. Rom total energy calculations, we showed that the FeSi-terminated surface was much more stable compared to the Fe-terminated one by the significant energy difference of 7 eV. The calculated magnetic moment (2.83 mu(B)) of the Fe-terminated surface was enhanced by about two times compared to that (1.30 mu(B)) of the corresponding bulk Fe whereas the calculated magnetic moment (2.87 mu(B)) of the Fe atom at the FeSi-terminated surface was enhanced only slightly compared with that (2.59 mu(B)) of the corresponding bulk Fe. It is quite interesting that the calculated spin polarization of the Fe-terminated surface at the Fermi level shows an almost half-metallic behavior, unlike the bulk behavior.