|AVS 65th International Symposium & Exhibition|
|Novel Trends in Synchrotron and FEL-Based Analysis Focus Topic||Thursday Sessions|
|Session:||Novel Trends in Synchrotron and FEL-Based Analysis Focus Topic Poster Session|
|Presenter:||Satoshi Yasuno, Japan Synchrotron Radiation Research Institute, Japan|
|Authors:||S. Yasuno, Japan Synchrotron Radiation Research Institute, Japan
N. Ikeno, Aichi Synchrotron Radiation Center, Japan
H. Oji, Nagoya University Synchrotron Radiation Research Center, Japan
|Correspondent:||Click to Email|
Hard X-ray photoelectron spectroscopy (HAXPES) has been attracting considerable attention since it can probe the chemical and electronic states of the bulk and buried interface lying at depths of several tens of nm due to its large probing depth. In the last decade, HAXPES have been applied to various research fields, such as electronic devices, organic materials, and rechargeable batteries. However, the quantitative analysis of the HAXPES measurement related to the relative sensitivity factors(RSFs), standard materials and theoretical calculations in hard X-ray region, have not previously been reported in detail. Therefore, in this study, we investigated the procedures of quantitative analysis for HAXPES and development of the RSFs data base in the hard X-ray region. Here, we focused the database of the RSFs of compounds provided by Wagner. According to Wagner’s RSFs principle, the absolute value of the sensitivity factor will vary with the matrix because of the variability of the mean free path λ, by contrast the relative sensitivity factor will hardly vary because the ratio λ1/λ2 for element 1 and 2, is only slightly with matrix dependence. Therefore, with the RSFs of compounds, the corrections related to the mean free path which largely influenced the number of photoelectron (signal intensity) are not needed for the quantitative analysis. For HAXPES, the core level peaks can be measured in a wide kinetic energy. Thus, it is suggested that the RSFs obtained by the compound is suitable for HAXPES measurement. In this study, the empirical sensitivity factors for the 1s, 2s, 2p3/2, 3d5/2 and 4f levels relative to O 1s were derived from HAXPES measurements with the photon energy of 6, 8, 10 keV. Comparing with the theoretical RSFs calculated from Hartee‐Slater cross sections reported by Scofield with combined energy dependence on the spectrometer function and the inelastic mean free path, the good agreement between the empirical and the theoretical RSF values were observed with several notable exceptions, while the discrepancies were observed in several energy regions.
This work was supported by the Hyogo Science and Technology Association Foundation. The synchrotron radiation experiments were performed at the BL46XU of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No.2017A1768, 2017B1600, 2017B1811, 2018A1563, 2018A1695 ).
 K. Kobayashi, Nucl. Instrum. Methods Phys. Res. A601, 32-47 (2009).
 C.D.Wagner et at., Surf. Interface Anal. 3, 211 (1981)