Surface segregation in FeSi alloys

Abstract The surface segregation of a Fe 94 Si 6 and Fe 76 Si 24 alloys was studied using high resolution photoemission spectroscopy with synchrotron radiation at 150–166 eV photon beam energy. During Ar + ion sputtering and following heat treatment, a SiO 2 layer and segregation of Si atoms in three clearly resolved phases occurred. This indicates formation of silicides, mainly Fe 3 Si and cubic FeSi superstructures. The photoemission measurements were complemented by 57 Fe Mossbauer spectroscopy in different modes which gave information about deeper surface layers (approximately 10–30 000 nm) of the samples. The results derived from the Mossbauer spectra support the conclusions concerning phase composition of the surface deduced from photoemission spectroscopy.