Dependence of core-level XPS spectra on iron silicide phase

► The clean iron silicide surfaces were prepared by fracturing the bulk sample. ► XPS spectra for Fe3Si, FeSi, and FeSi2 were collected from the clean surface. ► The silicides exhibited chemical shifts from elemental Fe in the Fe 2p spectra. ► The degree of asymmetry in the Fe 2p spectra was linked to Si content.