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-FeSi
single crystal studied by XPS and XASYamamoto, Hiroyuki; Esaka, Fumitaka
Photon Factory Activity Report 2010, Part B, P. 189, 2011/00
Semi-conducting silicides are extensively investigated for using as silicon-based electronic devices. Among silicides, -FeSi having a band gap of 0.85 eV is a candidate as a promising semiconductor. In the present study, a combination of XPS and XAS is applied to clarify surface chemical states of a -FeSi single crystal and a homoepitaxial -FeSi film. On the basis of the XPS spectra, surface oxide layers suggests that the thicknesses are estimated to be 1.0 nm and 0.8 nm for the single crystal and the homoepitaxial film, respectively. The obtained Si K-edge XAS spectra of the homoepitaxial film is similar to that of the single crystal, meaning that a homogeneous -FeSi film can be obtained in this condition. However, slight increases of the peaks at 1840.8 and 1844.3 eV in the spectrum of the homoepitaxial film suggest the presence of other chemical states such as FeSi.
Imazono, Takashi; Koike, Masato
Photon Factory Activity Report 2010, Part B, P. 318, 2011/00
A soft X-ray spectrograph to attach to electron microscopes has been developed. Original TEM-SXES instruments can detect soft X-ray emission (SXE) spectra of the 60-2000 eV range. However it is necessary to develop a new SXES instrument that covers a much wider energy range. It is of importance to detect the SXE spectra from 2 keV to 4 keV. Observation of the SXE spectra in this energy range needs a multilayer grating because in which a typical grating with the gold coating is no longer practical. A conventional multilayer grating has high diffraction efficiency but narrow band at a fixed angle of incidence. It indicates that the SXES instrument should employ a mechanism for wavelength scanning to cover the required energy range and is unsuitable for the spectrograph to attach to a TEM. To overcome this problem, we have invented a new multilayer structure to uniformly enhance the reflectivity in a few keV energy range at a fixed angle of incidence.
