Terauchi, Masami*; Imazono, Takashi; Koike, Masato
Hyomen Kagaku, 36(4), p.184 - 188, 2015/04
Electron beam induced soft-X-ray emission spectroscopy (SXES) that uses a grating spectrometer has been introduced to a conventional scanning electron microscope (SEM) for characterizing desired specimen areas of bulk materials. The spectrometer has a grazing-incidence flat-field optics by using aberration corrected (varied-line-spacing) gratings, which has already been applied to transmission electron microscopes. The best resolution was confirmed as 0.13 eV at Mg L-emission (50 eV), which is comparable with that of recent dedicated electron energy-loss spectroscopy instruments. Apparent band structure effects have been observed in Mg-L, Si-L, B-K, and Ti-L emission spectra obtained from bulk materials using SEM-SXES instrument.
Koike, Masato; Imazono, Takashi; Ishino, Masahiko
X-sen Bunseki No Shimpo, 46, p.159 - 166, 2015/03
The demand for the physical-properties research using powerful light sources, such as synchrotron radiation and soft-X-rays laser light, is increasing. When promoting such research, it is required to develop efficient soft-X-ray spectrometers suitable for absorption, emission, and fluorescence which are appeared in an energy rage of 1-8 keV. We describe the development of laminar type diffraction gratings which enhance diffraction efficiency remarkably by use of soft-X-ray multilayers instead of single metal layers.
Terauchi, Masami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Imazono, Takashi; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; et al.
Microscopy and Microanalysis, 20(Suppl.3), p.682 - 683, 2014/08
X-rays originate form electronic transitions from valence bands (VB, bonding electron states) to inner-shell electron levels inform us energy states of bonding electrons. We have developed the SXES spectrometers attaching to TEM, EPMA, and SEM. A spectrometer has an energy range of 50-4000 eV by using four varied-line-spacing gratings. Applications of TEM-SXES instrument to C have revealed characteristic energy distribution of bonding electrons. Carbon K-emission spectra of C crystals showed that both the peak structures in - and -bands and the characteristic dip structure between the - and -bonding states in monomer-C disappear in the most polymerized-C crystals. Bulk specimens were examined by applying SXES to a SEM. Al L-emission spectra of intermetallic compounds of AlAu, AlCo, and aluminum showed different intensity distributions due to different band structures originating from different crystal structures.
Microscopy and Microanalysis, 20(Suppl.3), p.684 - 685, 2014/08
A novel wavelength dispersive soft X-ray emission spectrometer (SXES) having a X-ray energy range of 50-210 eV has been developed. One feature is that the SXES is parallel detection of the signals so that it can be used like a conventional energy dispersive spectrometer. The other is a high energy resolution, which is about 0.2 eV at Al-L comparable to those revealed by XPS and EELS. These features enable us to obtain meaningful information about chemical bonding in various bulk samples. The SXES can detect Li-K emission spectrum. In the case of an anode electrode of a lithium ion battery (LIB), two types of lithium peaks are observed: one lower energy peak at 50 eV and the other higher energy peak at 54 eV. It was found that the former peak corresponds to the amount of charging, whereas the latter corresponds to the metallic state of lithium.
Terauchi, Masami*; Koshiya, Shogo*; Sato, Futami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Imazono, Takashi; Koeda, Masaru*; Nagano, Tetsuya*; et al.
Microscopy and Microanalysis, 20(3), p.692 - 697, 2014/06
Electron beam induced soft-X-ray emission spectroscopy (SXES) by using a grating spectrometer has been introduced to a conventional scanning electron microscope (SEM) for characterizing desired specimen areas of bulk materials. The spectrometer was designed as a grazing-incidence flat-field optics by using aberration corrected (varied-line-spacing) gratings and a multi-channel-plate detector combined with a charge-coupled-device camera, which has already applied for a transmission electron microscope. The best resolution was confirmed as 0.13 eV at Mg L-emission (50 eV), which value is comparable to that of recent dedicated electron energy-loss spectroscopy instruments. This SXES-SEM instrument presents density of states of simple metals of bulk Mg and Li. Apparent band structure effects have been observed in Si L-emission of Si-wafer, P L-emission of GaP-wafer, and Al L-emissions of intermetallic compounds of AlCo, AlPd, AlPt, and AlAu.
Oyo Butsuri, 83(4), p.288 - 292, 2014/04
We have developed a soft X-ray flat-field spectrograph capable to detect soft X-ray emissions in 50-4000 eV with high spectral resolution. The spectrograph in combination with an electron microscope such as transmission electron microscope (TEM) and electron probe micro-analyzer (EPMA) makes it possible to simultaneously perform not only the structural and elemental analyses of such functional materials as lithium-ion batteries and solar cells, but also chemical-bonding states analysis in the nano-scale area. In this article, the development of the soft X-ray flat-field spectrograph and preliminary experimental results measured by the spectrograph installed in EPMA and TEM are described.
Terauchi, Masami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; et al.
JAEA-Conf 2013-001, p.77 - 80, 2013/09
We have been developing a soft X-ray emission spectroscopy (SXES) instrument for electron microscopes (TEM, EPMA/SEM) with an extension of detectable energy range to 50-4000 eV. An introduction of valence electron spectroscopy with microscopy will supply fruitful information on bonding electrons, which cannot be obtained by EELS and EDS. For extend the lowest (or highest) detection energy upto 50 eV (or 4000 eV), a new laminar-type varied-line-spacing (VLS) grating, JS50XL, (or JS4000) has designed and manufactured. JS50XL and JS4000 having 1200 and 2400 lines/mm as well as coated by Au and a new multilayer-structure of W/BC for a wide-band energy region of 2000-3800 eV, respectively. Those gratings were installed and tested in a SXES spectrometer attached to a TEM. The extension in lowest detection energy was confirmed by Mg-L emission (JS50XL). The energy resolution was 0.2 eV at Fermi edge of 49.5 eV. It can be also seen a sharp Fermi edge for Li-K emission spectrum of metal-Li. The high energy resolution was confirmed by Te-La emission at 3.8 keV (JS4000). The full width at half maximum of the peak was 27 eV. The detection energy range was successfully extended by using the two new VLS-gratings.
Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Terauchi, Masami*; Koeda, Masaru*; Nagano, Tetsuya*; et al.
JAEA-Conf 2013-001, p.13 - 15, 2013/09
A very unique high performance soft X-ray emission spectrometer (SXES) has successfully been developed which can be attached not only to transmission electron microscopes (TEMs), but also to scanning electron microscopes (SEMs) as well as electron probe microanalyzers (EPMAs). To extend the analyzed energy ranges, a newly designed laminar-type varied-line-spacing (VLS) grating JS50XL, for a lower energy range, 50-170 eV, and a multilayered VLS grating JS4000, for a higher energy range, 2000-4000 eV, have been developed and installed to this spectrometer. Application software has also been developed for a commercial use of SXES in several fields such as battery materials, steel and alloys, and electron devices. The appearance of this spectrometer attached to EPMA and a few results acquired are shown in the following figures. This development has been conducted as one of the projects of Collaborative Development of Innovative Seeds (Practicability verification stage) by Japan Science and Technology Agency.
Imazono, Takashi; Koike, Masato; Kawachi, Tetsuya; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; Yonezawa, Zeno*; Kuramoto, Satoshi*; et al.
Proceedings of SPIE, Vol.8848, p.884812_1 - 884812_14, 2013/09
We have developed an objective soft X-ray flat-field spectrograph to be able to attach to electron microscopes. This spectrograph has two attractive features. One is that it is designed to cover a wide energy range of 50-4000 eV by using four varied-line-spacing holographic gratings optimized for 50-200 eV, 155-350 eV, 300-2200 eV, and 2000-4000 eV. They can be accommodated in the single spectrograph. The other is a newly invented W/BC multilayer coating covering the 2000-4000 eV range. It can enhance the diffraction efficiency above a practical level of % at a constant incidence angle in the whole energy range.
Microscopy and Microanalysis, 19(Suppl.2), p.1258 - 1259, 2013/08
A new wavelength dispersive soft X-ray emission spectrometer (WD-SXES) consisting of newly developed diffraction gratings has been developed for soft X-ray emission spectroscopy. The WD-SXES with two types of diffraction gratings nominally covering an energy range between 50 and 210 eV has been installed to electron probe X-ray microanalyzers, JEOL JXA-8100, for commercial use. The energy resolution of this WD-SXES is nominally 0.3 eV, which is one order of magnitude better than that of conventional WDSs with layered dispersion elements. It is to be noted that the corresponding edge of AlB is shifted to higher energy side by about 1 eV. One of the energy range was selected from 72 to 73.5 eV whereas the other was from 73.5 to 75 eV. The contrast in the former map is reversed in the later map as expected even though the energy difference between two maps is only 1.5 eV. The study confirms the high potential for the characterization especially for chemical state mapping.
Microscopy and Microanalysis, 19(Suppl.2), p.1278 - 1279, 2013/08
We have been developed and tested soft-X-ray emission spectroscopy (SXES) instruments by attaching to TEM and EPMA. The spectrometer has an energy range form 50-4000 eV by using four varied-line-spacing (aberration corrected) gratings. This SXES spectrometer inform us energy states of valence electrons (bonding electrons) form an identified specimen area by electron microscopy, which cannot be obtained by EELS and EDS. This provides not only the probing method for the energy states of valence electrons but also a sensitive tool for elemental and chemical identification. The spectrometer has applied also to a SEM (JEOL JSM-6480LV). As SEM can use a larger probe current and excitation volume of specimen than those of TEM, the detection time is about one order shorter than that of TEM. The energy resolution evaluated at AL-Ledge is 0.16 eV. The spectrum of LaB shows apparent intensity corresponds to B-K Fermi edge, showing chemical state of boron.
Microscopy, 62(3), p.391 - 395, 2013/06
A new multilayer-coated varied line-spaced grating, JS4000, was fabricated and tested for extending the upper limit of a grating X-ray spectrometer for electron microscopy. This grating was designed for 2-3.8 keV at a grazing incidence angle of 1.35 deg. It was revealed that this new multilayer structure enables us to take soft-X-ray emission spectra continuously from 1.5 keV to 4 keV at the same optical setting. The full-width at half maximum of Te-L (3.8 keV) emission peak was 27 eV. Sn-L (3444 eV) and In-L (3487 eV) peaks, which cannot be resolved by a widely used energy-dispersive X-ray spectrometer.
JEOL News, 47(1), p.23 - 28, 2012/07
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.
Journal of Electron Microscopy, 61(1), p.1 - 8, 2012/02
A new grating (JS50XL) for spectroscopy of ultrasoft-X-ray in an energy range of 50-200 eV was designed, manufactured and tested. A spectrometer composed of the grating and a multi-channel plate (MCP) detector was constructed. At the low energy end of this spectrometer, a sharp Fermi-edge of Mg-L emission was observed at 49.5 eV with an energy resolution of 0.15 eV. Li-K emission spectra were obtained from metal-Li, surface-oxidized metal-Li and 5%Li-Al. Relative energy shifts observed in Al-L emission spectra of Al, AlN and MgAlO were explained by shifts of core binding energies (chemical shift) and band gap energies of those materials. Si-L emissions from Si, SiC and SiO (quartz), and P-L emissions from GaP and InP were presented. These ultrasoft-X-ray emission spectra show a successful extension to lower energy range by using the new soft-X-ray emission spectroscopy (SXES) instrument in electron microscopy.
Nippon Denshi Nyusu, 44, p.11 - 16, 2012/00
Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Terauchi, Masami*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; et al.
Nippon Denshi Nyusu, 44, p.50 - 54, 2012/00
The soft-X-rays spectroscope developed for transmission electron micro scopes (TEM) so far was carried in the electron probe microanalyzer (EPMA). A combination of a newly developed varied-line-spacing (VLS) diffraction grating of JS50XL, and back-illumination type CCD is capable to observe a spectrum simultaneously in an energy region from 50 to 170 eV. In Al-L emission of an aluminum metal, 0.2 eV or less of high energy resolution was obtained. A clear Fermi edge and electronic density of states could be also observed, and the analysis of state in the minute domain became possible. For boron analysis, a VLS diffraction grating of JS200N (energy range: 70-210 eV) was produced, and super-light element analysis in steel of a 10 ppm level also became possible with the analytical curve determination method.
Imazono, Takashi; Kuramoto, Satoshi*; Koike, Masato
Photon Factory Activity Report 2011, Part B, P. 416, 2012/00
A soft X-ray spectrograph to attach to transmission 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 wider energy range 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 a 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, a new multilayer structure was invented, which uniformly enhances the reflectivity in a few keV energy range at a fixed angle of incidence. The multilayer was deposited on a laminar varied-line-spacing replica grating. The diffraction efficiency of the multilayer grating was evaluated by a goniometric apparatus, soft X-ray diffractometer, at a double-crystal Si monochromator BL-11B at Photon Factory, KEK. It varies from 0.6% to 2.7% over the whole energy range. This means the wide-band multilayer replica grating was developed successfully.
Proceedings of Microscopy and Microanalysis 2011 (Internet), 2 Pages, 2011/08
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.
Microscopy and Microanalysis, 17(Suppl.2), p.604 - 605, 2011/07
We have been developing a soft X-ray emission spectroscopy (SXES) instrument for TEM. SXES combined with microscopy should be a hopeful method to reveal physical properties and chemical bonding states of identified small specimen areas of various compounds. Original SXES instruments for conventional transmission electron microscopes basically designed to detect from 60 eV to 1200 eV (or 2000 eV in extended version). For applying to material science, a much wider energy range is necessary. Thus, a new SXES development for electron microscope has started to obtain an energy range from 50 eV to 3800 eV. An extension in lower energy region was achieved by a new aberration corrected (varied-line-spaced: VLS) grating. Conventional gratings in soft-X-ray energy region have gold surface. Au has M-absorption edge at 2.2 keV and shows only a small reflectance higher than the energy. Thus, a new multilayer-coated (MLC) VLS grating has designed and manufactured for obtaining SXES spectra up to 4 keV at a grazing incident angle of 1.35 deg. This development is conducting as one project of Collaborative Development of Innovative Seeds (Practicability verification stage) by Japan Science and Technology Agency.
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.