TY - JOUR
T1 - Development of wavelength-dispersive soft X-ray emission spectrometers for transmission electron microscopes - An introduction of valence electron spectroscopy for transmission electron microscopy
AU - Terauchi, Masami
AU - Koike, Masato
AU - Fukushima, Kurio
AU - Kimura, Atsushi
N1 - Funding Information:
The authors thank Mr F. Sato for his skillful technical assistance. The authors also thank Prof. S. Yamanaka of Hiroshima University and Prof. A.P. Tsai of Tohoku University for supplying the monomer C60 crystals and α-brass alloys, respectively, and Mr D. Naito for his preliminary SXES experiments on α-brass alloys. Present constructions of SXES spectrometers were conducted under the name ‘Development of an EELS/XES electron microscope for electronic structure analyses’, which was one of the leading projects of the Ministry of Education, Culture, Sports, Science and Technology, Japan. An application for carbon materials was supported by a Grant-in-Aid for Scientific Research on Priority Areas ‘New Materials Science Using Regulated Nano Spaces—Strategy in Ubiquitous Elements’ by the Ministry of Education, Culture, Sports, Science and Technology of Japan (No. 19051002).
PY - 2010/8
Y1 - 2010/8
N2 - Two types of wavelength-dispersive soft X-ray spectrometers, a high-dispersion type and a conventional one, for transmission electron microscopes were constructed. Those spectrometers were used to study the electronic states of valence electrons (bonding electrons). Both spectrometers extended the acceptable energy regions to higher than 2000 eV. The best energy resolution of 0.08 eV was obtained for an Al L-emission spectrum by using the high-dispersion type spectrometer. By using the spectrometer, C K-emission of carbon allotropes, Cu L-emission of Cu1-xZnx alloys and Pt M-emission spectra were presented. The FWHM value of 12 eV was obtained for the Pt Mα-emission peak. The performance of the conventional one was also presented for ZnS and a section specimen of a multilayer device. W-M and Si-K emissions were clearly resolved. Soft X-ray emission spectroscopy based on transmission electron microscopy (TEM) has an advantage for obtaining spectra from a single crystalline specimen with a defined crystal setting. As an example of anisotropic soft X-ray emission, C K-emission spectra of single crystalline graphite with different crystal settings were presented. From the spectra, density of states of π- and σ-bondings were separately derived. These results demonstrated a method to analyse the electronic states of valence electrons of materials in the nanometre scale based on TEM.
AB - Two types of wavelength-dispersive soft X-ray spectrometers, a high-dispersion type and a conventional one, for transmission electron microscopes were constructed. Those spectrometers were used to study the electronic states of valence electrons (bonding electrons). Both spectrometers extended the acceptable energy regions to higher than 2000 eV. The best energy resolution of 0.08 eV was obtained for an Al L-emission spectrum by using the high-dispersion type spectrometer. By using the spectrometer, C K-emission of carbon allotropes, Cu L-emission of Cu1-xZnx alloys and Pt M-emission spectra were presented. The FWHM value of 12 eV was obtained for the Pt Mα-emission peak. The performance of the conventional one was also presented for ZnS and a section specimen of a multilayer device. W-M and Si-K emissions were clearly resolved. Soft X-ray emission spectroscopy based on transmission electron microscopy (TEM) has an advantage for obtaining spectra from a single crystalline specimen with a defined crystal setting. As an example of anisotropic soft X-ray emission, C K-emission spectra of single crystalline graphite with different crystal settings were presented. From the spectra, density of states of π- and σ-bondings were separately derived. These results demonstrated a method to analyse the electronic states of valence electrons of materials in the nanometre scale based on TEM.
KW - anisotropic soft X-ray emission
KW - chemical shift
KW - soft X-ray emission spectroscopy
KW - transmission electron microscope
KW - valence band
KW - wavelength-dispersive spectroscopy
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U2 - 10.1093/jmicro/dfq010
DO - 10.1093/jmicro/dfq010
M3 - Article
C2 - 20371492
AN - SCOPUS:77955537746
VL - 59
SP - 251
EP - 261
JO - Microscopy (Oxford, England)
JF - Microscopy (Oxford, England)
SN - 2050-5698
IS - 4
ER -