Surface analysis of single-crystalline β-FeSi2

Abstract Clean surfaces of the single crystalline β - FeSi 2 have been prepared and investigated by means of surface analysis techniques. X-ray photoelectron spectroscopy of the surface oxide reveals that the surface Si is mainly oxidized while Fe isn’t. After removing the surface oxide, clean surface can be obtained showing well-defined atomic features in low-energy electron diffraction and scanning tunneling microscopy. No drastic surface reconstruction is found possibly reflecting strong Fe–Si bond. Density functional theory calculation suggests the spin polarized surface electronic density of states when Fe comes at the surface, although such a situation seems to be unlikely.