Spectroscopic characterization of -FeSi single crystals and homoepitaxial -FeSi films by XPS and XAS

Esaka, Fumitaka  ; Yamamoto, Hiroyuki; Udono, Haruhiko*; Matsubayashi, Nobuyuki*; Yamaguchi, Kenji; Shamoto, Shinichi  ; Magara, Masaaki  ; Kimura, Takaumi 

Chemical state analysis by a combination of X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) using synchrotron radiation is performed for -FeSi single crystals and homoepitaxial -FeSi films. The Si 2p XPS and Fe L-edge XAS spectra imply that the annealing at 1173 K to remove native oxide layers on the crystal induces the formation of FeSi in the surface. The formation of FeSi is also confirmed by Si K-edge XAS analysis. For the homoepitaxial -FeSi films grown on the crystals, the Si K-edge XAS spectra indicate that structurally homogeneous -FeSi films can be grown on the -FeSi single crystals when the substrate temperatures of 973 and 1073 K are applied for molecular beam epitaxy (MBE). Consequently, it is indicated that the combination of XPS and XAS using synchrotron radiation is a useful tool to clarify chemical states nondestructively.