A New WDS spectrometer for valence electron spectroscopy based on electron microscopy

新WDS装置を用いた軟X線発光分光による価電子状態分析

寺内 正己*; 高橋 秀之*; 飯田 信雄*; 村野 孝訓*; 小池 雅人; 河内 哲哉; 今園 孝志; 小枝 勝*; 長野 哲也*; 笹井 浩行*; 大上 裕紀*; 米澤 善央*; 倉本 智史*

Terauchi, Masami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; Yonezawa, Zeno*; Kuramoto, Satoshi*

これまで透過型電子顕微鏡用に研究開発されてきた軟X線発光分光装置の分光エネルギー領域を拡張し、TEMだけでなくEPMA/SEMに搭載可能な軟X線発光分析システムの開発を行った。ここでは、50-200eV用に開発した回折格子JS50XLを用いた測定例として、単純金属のMg-L発光, Li-K発光, Al-L発光, Be-K発光を示す。これらのスペクトル強度分布は、価電子の状態密度分布とシャープなフェルミ端を明瞭に示した。また、半導体であるSiと金属であるTiSiのSi-L発光スペクトルの比較、及び、CaBとLaBのB-K発光スペクトルの比較を示す。

A new WDS spectrometer for a transmission electron microscope has been constructed. This spectrometer can cover an energy region from 50 eV to 3800 eV by using four aberration-corrected gratings for flat-field optics. By using a newly designed and manufactured grating of JS50XL for 50-200 eV, soft-X-ray emission spectra of simple metals of Mg, Li, Al and Be were measured. Those intensity profiles correspond to partial density of states of valence electrons (bonding electrons) and also showed clear Fermi edges (top of the occupied state). At the Fermi edge of Mg-L emission (49.5 eV), an energy resolution was evaluated to be 0.16 eV. Si-L emission spectra of Si and TiSi show a difference in those intensity distributions, indicating different valence-electron states for those materials. A comparison of B-K emission spectra of CaB and LaB, which were obtained by using another grating of JS200N, is shown.