A Newly developed grating and soft X-ray spectrometer for electron probe microanalyser and transmission electron microscope; An Acquisition of the Li K emission spectrum with high-energy resolution and detection of light elements

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

Soft X-ray spectroscopy with high-energy resolution gives useful information of the chemical bonding states in compounds. Terauchi et al. recently reported a high-energy resolution of 0.2 eV in the Al-L emission spectrum using the previously developed soft X-ray Emission spectrometer (SXES) with a transmission electron microscope. This spectrometer can design to detect the energy from 60 to 1200 eV. In order to progress this result, we had attempted to enhance the detection energy range. Especially to detect the Li-K emission spectrum, we are developing a spectrometer with newly designed aberration corrected gratings. The newly developed grating JS50XL can cover the X-ray energy range from 50 to 200eV with the high energy resolution. It actually means to detect Li-K (55 eV), Al-L (70 eV), Si-L (100 eV), B-K (180 eV) and high order of C-K (279 eV), N-K (392 eV), O-K (525 eV) and so on. This SXES can be equipped not only with TEM, but also with EPMA. Moreover, we found out that attached EPMA with SXES has another strong feature that the X-ray intensity is in directly proportional to probe current. This feature is very useful for the trace element analysis. In the case of Li-K, Be-K and B-K emissions, the detection limits have been evaluated to be a few tens of ppm. For example trace boron analysis is expected to evaluate the newly developed materials quantitatively. This developed spectrometer is hopeful to observe chemical bonding state and trace element analysis in many kinds of fields. In this presentation we report the results for fundamental and actual samples. This development is conducting as one project of Collaborative Development of Innovative Seeds (Practicability verification stage) by Japan Science and Technology Agency.