Tetsuo Oikawa - Academia.edu (original) (raw)
Papers by Tetsuo Oikawa
Journal of Electron Microscopy, 1995
Proceedings, annual meeting, Electron Microscopy Society of America, 1987
The “Imaging Plate”(IP) is a highly sensitive image recording plate for X-ray radiography. It has... more The “Imaging Plate”(IP) is a highly sensitive image recording plate for X-ray radiography. It has been ascertained that the IP has superior properties and high practicability as an image recording material in a TEM. The sensitivity, one of the properties, is about 3 orders higher than that of conventional photo film. The IP is expected to be applied to low dose techniques. In this paper, an estimation of the quantum noise on the TEM image which appears in case of low electron dose on the IP is reported.In this experiment, the JEM-2000FX TEM and an IP having the same size as photo film were used.Figure 1 shows the schematic diagram of the total system including the TEM used in this experiment. In the reader, He-Ne laser light is scanned across the IP, then blue light is emitted from the IP.
Journal of Electron Microscopy, 1986
Journal of Electron Microscopy, 1985
A digital filter called the top-hat filter is very useful for processing EELS spectra: strong bac... more A digital filter called the top-hat filter is very useful for processing EELS spectra: strong background suppression almost removes the steep slope of AE~2 3 in spectra; in filtered spectra, tiny core-edges of microelements can be more easily detected and identified than in original ones; and by the change of the filter width as the needs of the case demand, an adequate filtered spec-trum can be obtained (expanding the filter width enables us to emphasize the existence of a core-edge and minimizing the filter width allows preservation of the fine structure of a core-edge). Key words = digital processing: top-hat filter (THF): electron energy loss spec-troscopy (EELS): qualitative analysis: core-edge
Microscopy Research and Technique, 2018
Green culms of Bambusa multiplex and the bamboo charcoal carbonized from the green culms at 700°C... more Green culms of Bambusa multiplex and the bamboo charcoal carbonized from the green culms at 700°C have been studied by means of X‐ray diffraction, X‐ray fluorescent element analysis, analytical scanning electron microscopy, and analytical scanning transmission electron microscopy (STEM), aiming at industrial applications as raw materials for functional devices and substances. It is revealed that the green culms and the charcoal contain a significant amount of Si, in particular, ∼18 wt % in the skin. The green culms comprise amorphous and crystalline celluloses. The charcoal has a so‐called amorphous structure which is composed of randomly distributed carbon nanotubes and fibers. The growth of Ag‐doped activated charcoal powders that were produced by two different methods using this charcoal powder has also been studied.
Journal of the Japan Institute of Metals, 1993
Acta Crystallographica Section C Structural Chemistry, 2017
A combination of solid-state NMR (ssNMR) and electron diffraction (ED) has been used to determine... more A combination of solid-state NMR (ssNMR) and electron diffraction (ED) has been used to determine the crystalline polymorphs in small-organic microcrystalline molecules. Although 13C cross-polarization magic angle spinning (CPMAS) is a widely used method for determining crystalline polymorphs, even in a mixture, it sometimes fails if the molecular conformations are similar. On the other hand, ED can, in principle, differentiate crystalline forms with different lattice parameters, even when they have very similar molecular conformations. However, its application is usually limited to inorganic molecules only. This is because the ED measurements of organic molecules are very challenging due to degradation of the sample by electron irradiation. We overcame these difficulties by the use of 1H double-quantum/single-quantum correlation experiments at very fast magic angle spinning, together with ED observations under mild electron irradiation. The experiments were demonstrated on L-histid...
Journal of Electron Microscopy, 1990
Electron diffraction patterns of a Cu 3 Pd alloy were quantitatively analyzed by making good use ... more Electron diffraction patterns of a Cu 3 Pd alloy were quantitatively analyzed by making good use of a wide dynamic range and good linearity of the imaging plate dedicated to an electron microscope. Intensities of both fundamental and superlattice reflections of the alloy having a one-dimensional long-period superstructure were measured in situ as a function of the temperature. The intensity changes of the superlattice reflections quantitatively evaluated clearly show the characteristic disordering process of the Cu 3 Pd alloy. It was demonstrated that quantitative structure analysis by electron diffraction patterns is possible with the use of the imaging plate if the dynamical diffraction effect is taken into account.
Materials Science in Semiconductor Processing, 2015
ABSTRACT
EMC 2008 14th European Microscopy Congress 1–5 September 2008, Aachen, Germany, 2008
It is now well known that physical and chemical properties of nanoparticles depend not only on th... more It is now well known that physical and chemical properties of nanoparticles depend not only on their size but also on three-dimensional (3D) morphology. Therefore, the knowledge of those parameters is crucial and their accurate measurement highly desirable. Recently, electron tomography has made huge progress both in the acquisition and the reconstruction processes [1, 2]. The acquisition is now automated
Analytical Electron Microscopy for Materials Science, 2002
Electron diffraction is fundamentally one of the most important methods for obtaining crystallogr... more Electron diffraction is fundamentally one of the most important methods for obtaining crystallographic information about materials. The information obtained by electron diffraction is the quantity in reciprocal space, which is the same as that attained by X-ray diffraction and neutron diffraction. Although the intensity of X-ray diffraction and neutron diffraction directly corresponds to the square of an absolute value of the structure factor according to the kinematical diffraction theory, the intensity of electron diffraction should be interpreted on the basis of the dynamical diffraction theory. The dynamical diffraction effect on electron diffraction is explained in the literature [1-3]. In this chapter we discuss the principles and application of nano-beam electron diffraction and convergent beam electron diffraction, which extensively utilize the function of an analytical electron microscope.
Analytical Electron Microscopy for Materials Science, 2002
The constitution, functions, and principles of an analytical electron microscope are explained in... more The constitution, functions, and principles of an analytical electron microscope are explained in this chapter. For observing electron microscope images and diffraction patterns and for carrying out various extensive analyses, it is important to set an analytical electron microscope to be in optimal operating condition by learning the principles of its constituent units and its appropriate operating method. Here, the basic configuration of a transmission electron microscope is noted first, and its constituent units are described in turn. Alignment of various lens axes and adjustment of their astigmatism are explained based on these explanations.
Microscopy and Microanalysis, 2007
Extended abstract of a paper presented at Microscopy and Microanalysis 2007 in Ft. Lauderdale, Fl... more Extended abstract of a paper presented at Microscopy and Microanalysis 2007 in Ft. Lauderdale, Florida, USA, August 5 – August 9, 2007
Journal of Electron Spectroscopy and Related Phenomena, 1982
An interband n plasmon and n * edge have been observed in the spectrum of hexagonal boron nitride... more An interband n plasmon and n * edge have been observed in the spectrum of hexagonal boron nitride (h-BN). This result is in good agreement with that for graphite. On the other hand, the interband u plasmon and U* edge which have been observed in the spectra of both cubic boron nitride (c-BN) and wurtzite boron nitride (w-BN) are in good agreement with results for diamond. These results show that there is structural similarity between h-BN and graphite and among c-BN, w-BN and diamond, giving rise to spectral similarities for both the plasmon-loss and core-edge spectra. There is a difference in fine structure on the K edge between c-BN and w-BN. The energy values for the fine structure on the K edge are in agreement with the band structure calculated at symmetry points of the Brillouin zone.
Journal of Electron Microscopy, 1998
... 5 Park K H. Hashimoto S, Kawasaki M, and Ibe K (1995) Sub-nanometric elemental analysis on UL... more ... 5 Park K H. Hashimoto S, Kawasaki M, and Ibe K (1995) Sub-nanometric elemental analysis on ULSI devices with FEG-TEM. ... 8 Murakoshi H, Kakibayashi H, and Tsuchiya T (1996) High resolution X-ray elemental mapping using 300-kV field emission TEM. J. Electron Microsc. ...
Geochimica et Cosmochimica Acta, 2008
We report the mineral compositions and micro-texture of the isotopically anomalous (d 17,18 O SMO... more We report the mineral compositions and micro-texture of the isotopically anomalous (d 17,18 O SMOW $ +180&) Fe-S-Ni-O material recently discovered in matrix of the primitive carbonaceous chondrite Acfer 094 [Sakamoto N., Seto Y., Itoh S., Kuramoto K., Fujino K., Nagashima K., Krot A. N. and Yurimoto H. (2007) Oxygen isotope evidence for remnants of the early solar system primordial water. Science 317, 231-233]. Synchrotron radiation X-ray diffraction and transmission electron microscopy studies indicate that this material consists of the symplectitically intergrown magnetite (Fe 3 O 4) and pentlandite (Fe 5.7 Ni 3.3 S 8) with magnetite/pentlandite volume ratio of $2.3. Magnetite forms column-shaped grains (10-30 nm in diameter and 100-200 nm in length); pentlandite occurs as worm-shaped grains or aggregates of grains 100-300 nm in size between magnetite crystals. Although both the X-ray diffraction and electron energy loss spectra support identification of iron oxide as magnetite, the electron diffraction patterns show that magnetite has a weak 3-fold superstructure, possibly due to ordering of vacancies. We infer that the isotopically anomalous symplectite formed by sulfurization and oxidization of metal grains either in the solar nebula or on an icy planetesimal. The intersite cation distribution of pentlandite suggests that timescale of oxidation was no longer than 1000 years.
Acta Crystallographica Section A Foundations of Crystallography, 2002
The domain structures of a ferroic triad of materials with the formula Zn3B7O13X, where X=Cl, Br ... more The domain structures of a ferroic triad of materials with the formula Zn3B7O13X, where X=Cl, Br and I have been analyzed by transmission electron microscopy (TEM) and polarised light microscopy (PLM). Zn3B7O13X boracites exhibit a high temperature phase of cubic prototype symmetry F43c. The domain structure of Zn3B7O13Cl as observed by TEM and PLM indicates a trigonal symmetry at room temperature whilst those of Zn3B7O13Br and Zn3B7O13I indicate an orthorhombic symmetry at the same temperature. TEM work allowed to observe two different types of domains: First, domains due to the ferroic cubic to orthorhombic phase transition. These are in pseudomerohedral twin relations, and therefore they show weak contrasts in brightfield as well as in dark-field images. Second, thin (10 to 20 nm) lamellae parallel to (100, which can be explained as microtwins due to the Pca21 to the ferroic phase transformation. In some crystal grains the 'reaction front' of the transformation is preserved at room temperature and irregular inter-grow of the twin domains is observed. In situ heating experiments point out that the reversible phase transitions have strong hysteresis and the domains show no memory effects. Occasionally, an incommensurable modulation (q = 0.492(10)a*) at temperatures somewhat above the second transformation has been observed. This could represent a precursor of the micro-twinning. Support from Conacyt-Mexico (Project 34959E) and Deutsche Forschungemeinschaft is gratefully acknowledged.
MRS Proceedings, 1985
ABSTRACTElectron energy-loss spectroscopy in the transmission electron microscopy (TEELS) is a po... more ABSTRACTElectron energy-loss spectroscopy in the transmission electron microscopy (TEELS) is a powerful technique to investigate the “electron and atom interaction in specimen microareas”.This paper reports some experimental data of TEELS concerning specimen thickness effect and advantages of 400 kV TEM, and introduces newly developed digital processing of EELS spectra, which is a powerful technique to get the information from the specimen materials.
Journal of Electron Microscopy, 1995
Proceedings, annual meeting, Electron Microscopy Society of America, 1987
The “Imaging Plate”(IP) is a highly sensitive image recording plate for X-ray radiography. It has... more The “Imaging Plate”(IP) is a highly sensitive image recording plate for X-ray radiography. It has been ascertained that the IP has superior properties and high practicability as an image recording material in a TEM. The sensitivity, one of the properties, is about 3 orders higher than that of conventional photo film. The IP is expected to be applied to low dose techniques. In this paper, an estimation of the quantum noise on the TEM image which appears in case of low electron dose on the IP is reported.In this experiment, the JEM-2000FX TEM and an IP having the same size as photo film were used.Figure 1 shows the schematic diagram of the total system including the TEM used in this experiment. In the reader, He-Ne laser light is scanned across the IP, then blue light is emitted from the IP.
Journal of Electron Microscopy, 1986
Journal of Electron Microscopy, 1985
A digital filter called the top-hat filter is very useful for processing EELS spectra: strong bac... more A digital filter called the top-hat filter is very useful for processing EELS spectra: strong background suppression almost removes the steep slope of AE~2 3 in spectra; in filtered spectra, tiny core-edges of microelements can be more easily detected and identified than in original ones; and by the change of the filter width as the needs of the case demand, an adequate filtered spec-trum can be obtained (expanding the filter width enables us to emphasize the existence of a core-edge and minimizing the filter width allows preservation of the fine structure of a core-edge). Key words = digital processing: top-hat filter (THF): electron energy loss spec-troscopy (EELS): qualitative analysis: core-edge
Microscopy Research and Technique, 2018
Green culms of Bambusa multiplex and the bamboo charcoal carbonized from the green culms at 700°C... more Green culms of Bambusa multiplex and the bamboo charcoal carbonized from the green culms at 700°C have been studied by means of X‐ray diffraction, X‐ray fluorescent element analysis, analytical scanning electron microscopy, and analytical scanning transmission electron microscopy (STEM), aiming at industrial applications as raw materials for functional devices and substances. It is revealed that the green culms and the charcoal contain a significant amount of Si, in particular, ∼18 wt % in the skin. The green culms comprise amorphous and crystalline celluloses. The charcoal has a so‐called amorphous structure which is composed of randomly distributed carbon nanotubes and fibers. The growth of Ag‐doped activated charcoal powders that were produced by two different methods using this charcoal powder has also been studied.
Journal of the Japan Institute of Metals, 1993
Acta Crystallographica Section C Structural Chemistry, 2017
A combination of solid-state NMR (ssNMR) and electron diffraction (ED) has been used to determine... more A combination of solid-state NMR (ssNMR) and electron diffraction (ED) has been used to determine the crystalline polymorphs in small-organic microcrystalline molecules. Although 13C cross-polarization magic angle spinning (CPMAS) is a widely used method for determining crystalline polymorphs, even in a mixture, it sometimes fails if the molecular conformations are similar. On the other hand, ED can, in principle, differentiate crystalline forms with different lattice parameters, even when they have very similar molecular conformations. However, its application is usually limited to inorganic molecules only. This is because the ED measurements of organic molecules are very challenging due to degradation of the sample by electron irradiation. We overcame these difficulties by the use of 1H double-quantum/single-quantum correlation experiments at very fast magic angle spinning, together with ED observations under mild electron irradiation. The experiments were demonstrated on L-histid...
Journal of Electron Microscopy, 1990
Electron diffraction patterns of a Cu 3 Pd alloy were quantitatively analyzed by making good use ... more Electron diffraction patterns of a Cu 3 Pd alloy were quantitatively analyzed by making good use of a wide dynamic range and good linearity of the imaging plate dedicated to an electron microscope. Intensities of both fundamental and superlattice reflections of the alloy having a one-dimensional long-period superstructure were measured in situ as a function of the temperature. The intensity changes of the superlattice reflections quantitatively evaluated clearly show the characteristic disordering process of the Cu 3 Pd alloy. It was demonstrated that quantitative structure analysis by electron diffraction patterns is possible with the use of the imaging plate if the dynamical diffraction effect is taken into account.
Materials Science in Semiconductor Processing, 2015
ABSTRACT
EMC 2008 14th European Microscopy Congress 1–5 September 2008, Aachen, Germany, 2008
It is now well known that physical and chemical properties of nanoparticles depend not only on th... more It is now well known that physical and chemical properties of nanoparticles depend not only on their size but also on three-dimensional (3D) morphology. Therefore, the knowledge of those parameters is crucial and their accurate measurement highly desirable. Recently, electron tomography has made huge progress both in the acquisition and the reconstruction processes [1, 2]. The acquisition is now automated
Analytical Electron Microscopy for Materials Science, 2002
Electron diffraction is fundamentally one of the most important methods for obtaining crystallogr... more Electron diffraction is fundamentally one of the most important methods for obtaining crystallographic information about materials. The information obtained by electron diffraction is the quantity in reciprocal space, which is the same as that attained by X-ray diffraction and neutron diffraction. Although the intensity of X-ray diffraction and neutron diffraction directly corresponds to the square of an absolute value of the structure factor according to the kinematical diffraction theory, the intensity of electron diffraction should be interpreted on the basis of the dynamical diffraction theory. The dynamical diffraction effect on electron diffraction is explained in the literature [1-3]. In this chapter we discuss the principles and application of nano-beam electron diffraction and convergent beam electron diffraction, which extensively utilize the function of an analytical electron microscope.
Analytical Electron Microscopy for Materials Science, 2002
The constitution, functions, and principles of an analytical electron microscope are explained in... more The constitution, functions, and principles of an analytical electron microscope are explained in this chapter. For observing electron microscope images and diffraction patterns and for carrying out various extensive analyses, it is important to set an analytical electron microscope to be in optimal operating condition by learning the principles of its constituent units and its appropriate operating method. Here, the basic configuration of a transmission electron microscope is noted first, and its constituent units are described in turn. Alignment of various lens axes and adjustment of their astigmatism are explained based on these explanations.
Microscopy and Microanalysis, 2007
Extended abstract of a paper presented at Microscopy and Microanalysis 2007 in Ft. Lauderdale, Fl... more Extended abstract of a paper presented at Microscopy and Microanalysis 2007 in Ft. Lauderdale, Florida, USA, August 5 – August 9, 2007
Journal of Electron Spectroscopy and Related Phenomena, 1982
An interband n plasmon and n * edge have been observed in the spectrum of hexagonal boron nitride... more An interband n plasmon and n * edge have been observed in the spectrum of hexagonal boron nitride (h-BN). This result is in good agreement with that for graphite. On the other hand, the interband u plasmon and U* edge which have been observed in the spectra of both cubic boron nitride (c-BN) and wurtzite boron nitride (w-BN) are in good agreement with results for diamond. These results show that there is structural similarity between h-BN and graphite and among c-BN, w-BN and diamond, giving rise to spectral similarities for both the plasmon-loss and core-edge spectra. There is a difference in fine structure on the K edge between c-BN and w-BN. The energy values for the fine structure on the K edge are in agreement with the band structure calculated at symmetry points of the Brillouin zone.
Journal of Electron Microscopy, 1998
... 5 Park K H. Hashimoto S, Kawasaki M, and Ibe K (1995) Sub-nanometric elemental analysis on UL... more ... 5 Park K H. Hashimoto S, Kawasaki M, and Ibe K (1995) Sub-nanometric elemental analysis on ULSI devices with FEG-TEM. ... 8 Murakoshi H, Kakibayashi H, and Tsuchiya T (1996) High resolution X-ray elemental mapping using 300-kV field emission TEM. J. Electron Microsc. ...
Geochimica et Cosmochimica Acta, 2008
We report the mineral compositions and micro-texture of the isotopically anomalous (d 17,18 O SMO... more We report the mineral compositions and micro-texture of the isotopically anomalous (d 17,18 O SMOW $ +180&) Fe-S-Ni-O material recently discovered in matrix of the primitive carbonaceous chondrite Acfer 094 [Sakamoto N., Seto Y., Itoh S., Kuramoto K., Fujino K., Nagashima K., Krot A. N. and Yurimoto H. (2007) Oxygen isotope evidence for remnants of the early solar system primordial water. Science 317, 231-233]. Synchrotron radiation X-ray diffraction and transmission electron microscopy studies indicate that this material consists of the symplectitically intergrown magnetite (Fe 3 O 4) and pentlandite (Fe 5.7 Ni 3.3 S 8) with magnetite/pentlandite volume ratio of $2.3. Magnetite forms column-shaped grains (10-30 nm in diameter and 100-200 nm in length); pentlandite occurs as worm-shaped grains or aggregates of grains 100-300 nm in size between magnetite crystals. Although both the X-ray diffraction and electron energy loss spectra support identification of iron oxide as magnetite, the electron diffraction patterns show that magnetite has a weak 3-fold superstructure, possibly due to ordering of vacancies. We infer that the isotopically anomalous symplectite formed by sulfurization and oxidization of metal grains either in the solar nebula or on an icy planetesimal. The intersite cation distribution of pentlandite suggests that timescale of oxidation was no longer than 1000 years.
Acta Crystallographica Section A Foundations of Crystallography, 2002
The domain structures of a ferroic triad of materials with the formula Zn3B7O13X, where X=Cl, Br ... more The domain structures of a ferroic triad of materials with the formula Zn3B7O13X, where X=Cl, Br and I have been analyzed by transmission electron microscopy (TEM) and polarised light microscopy (PLM). Zn3B7O13X boracites exhibit a high temperature phase of cubic prototype symmetry F43c. The domain structure of Zn3B7O13Cl as observed by TEM and PLM indicates a trigonal symmetry at room temperature whilst those of Zn3B7O13Br and Zn3B7O13I indicate an orthorhombic symmetry at the same temperature. TEM work allowed to observe two different types of domains: First, domains due to the ferroic cubic to orthorhombic phase transition. These are in pseudomerohedral twin relations, and therefore they show weak contrasts in brightfield as well as in dark-field images. Second, thin (10 to 20 nm) lamellae parallel to (100, which can be explained as microtwins due to the Pca21 to the ferroic phase transformation. In some crystal grains the 'reaction front' of the transformation is preserved at room temperature and irregular inter-grow of the twin domains is observed. In situ heating experiments point out that the reversible phase transitions have strong hysteresis and the domains show no memory effects. Occasionally, an incommensurable modulation (q = 0.492(10)a*) at temperatures somewhat above the second transformation has been observed. This could represent a precursor of the micro-twinning. Support from Conacyt-Mexico (Project 34959E) and Deutsche Forschungemeinschaft is gratefully acknowledged.
MRS Proceedings, 1985
ABSTRACTElectron energy-loss spectroscopy in the transmission electron microscopy (TEELS) is a po... more ABSTRACTElectron energy-loss spectroscopy in the transmission electron microscopy (TEELS) is a powerful technique to investigate the “electron and atom interaction in specimen microareas”.This paper reports some experimental data of TEELS concerning specimen thickness effect and advantages of 400 kV TEM, and introduces newly developed digital processing of EELS spectra, which is a powerful technique to get the information from the specimen materials.