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Nishi-Tokyo-shi, Japan

Kaneko K.,Kyushu University | Kaneko K.,Japan Science and Technology Agency | Kitawaki K.,Kyushu University | Sadayama S.,FEI Company Japan Ltd. | And 6 more authors.
Journal of Alloys and Compounds | Year: 2010

TiN nanocomposite powders with various morphologies were synthesized by DC arc-plasma method from Ti-Si ingot under N2-H2-Ar atmosphere. Microstructures of powders were characterized by powder X-ray diffraction method and transmission electron microscopy with compositional analysis, then morphologies by three-dimensional electron tomography. It was found that the powders were consisted of TiN nanoparticles covered by Ti5Si3 nanoparticles, which possibly suppressed the growth of facets and controlled the final morphologies of TiN-Ti5Si3 nanocomposite. © 2009 Elsevier B.V. Source

Yoshida K.,Japan Fine Ceramics Center | Yoshida K.,University of York | Yoshida K.,EcoTopia Science Institute | Bright A.,FEI Company Japan Ltd. | And 3 more authors.
Journal of Electron Microscopy | Year: 2012

We study in situ behavior of platinum single atoms on amorphous carbon (a-carbon) using a spherical aberration-corrected transmission electron microscope (AC-TEM). Diffusion of single atoms, bi-atoms, clusters (<1 nm) and nanoparticles (<3 nm) was recorded in the same image with a time resolution of 1 s, and such diffusion matches the expected mechanism of Ostwald ripening, which was seen on these samples. In situ AC-TEM shows promise for dynamical observation of single atom diffusion, which is important for understanding nanosized catalysts and ceramic sintering processes. We apply in situ AC-TEM to image platinum (Pt) nanoparticles on a-carbon, which is a model catalyst system for the real Pt electrode catalysts using alloys and core-shell structures supported on carbon/oxide composite materials in the proton exchange membrane fuel cell. © The Author 2012. Published by Oxford University Press [on behalf of Japanese Society of Microscopy]. All rights reserved. Source

Noda T.,Tokyo Medical University | Sugita Y.,Tokyo Medical University | Aoyama K.,FEI Company Japan Ltd. | Aoyama K.,Osaka University | And 10 more authors.
Nature Communications | Year: 2012

The influenza A virus genome consists of eight single-stranded negative-sense RNA (vRNA) segments. Although genome segmentation provides advantages such as genetic reassortment, which contributes to the emergence of novel strains with pandemic potential, it complicates the genome packaging of progeny virions. Here we elucidate, using electron tomography, the three-dimensional structure of ribonucleoprotein complexes (RNPs) within progeny virions. Each virion is packed with eight well-organized RNPs that possess rod-like structures of different lengths. Multiple interactions are found among the RNPs. The position of the eight RNPs is not consistent among virions, but a pattern suggests the existence of a specific mechanism for assembly of these RNPs. Analyses of budding progeny virions suggest two independent roles for the viral spike proteins: RNP association on the plasma membrane and the subsequent formation of the virion shell. Our data provide further insights into the mechanisms responsible for segmented-genome packaging into virions. © 2012 Macmillan Publishers Limited. All rights reserved. Source

Hata S.,Kyushu University | Miyazaki H.,Mel Build | Miyazaki S.,FEI Company Japan Ltd. | Mitsuhara M.,Kyushu University | And 9 more authors.
Ultramicroscopy | Year: 2011

Electron tomography requires a wide angular range of specimen-tilt for a reliable three-dimensional (3D) reconstruction. Although specimen holders are commercially available for tomography, they have several limitations, including tilting capability in only one or two axes at most, e.g. tilt-rotate. For amorphous specimens, the image contrast depends on mass and thickness only and the single-tilt holder is adequate for most tomographic image acquisitions. On the other hand, for crystalline materials where image contrast is strongly dependent on diffraction conditions, current commercially available tomography holders are inadequate, because they lack tilt capability in all three orthogonal axes needed to maintain a constant diffraction condition over the whole tilt range. We have developed a high-angle triple-axis (HATA) tomography specimen holder capable of high-angle tilting for the primary horizontal axis with tilting capability in the other (orthogonal) horizontal and vertical axes. This allows the user to trim the specimen tilt to obtain the desired diffraction condition over the whole tilt range of the tomography series. To demonstrate its capabilities, we have used this triple-axis tomography holder with a dual-axis tilt series (the specimen was rotated by 90° ex-situ between series) to obtain tomographic reconstructions of dislocation arrangements in plastically deformed austenitic steel foils. © 2011 Elsevier B.V. Source

Bright A.N.,FEI Company Japan Ltd. | Yoshida K.,Nagoya University | Yoshida K.,Japan Fine Ceramics Center | Tanaka N.,Japan Fine Ceramics Center | Tanaka N.,EcoTopia Science Institute
Ultramicroscopy | Year: 2013

Environmental transmission electron microscopy (ETEM) enables the study of catalytic and other reaction processes as they occur with Angstrom-level resolution. The microscope used is a dedicated ETEM (Titan ETEM, FEI Company) with a differential pumping vacuum system and apertures, allowing aberration corrected high-resolution transmission electron microscopy (HRTEM) imaging to be performed with gas pressures up to 20. mbar in the sample area and with significant advantages over membrane-type E-cell holders. The effect on image resolution of varying the nitrogen gas pressure, electron beam current density and total beam current were measured using information limit (Young's fringes) on a standard cross grating sample and from silicon crystal lattice imaging. As expected, increasing gas pressure causes a decrease in HRTEM image resolution. However, the total electron beam current also causes big changes in the image resolution (lower beam current giving better resolution), whereas varying the beam current density has almost no effect on resolution, a result that has not been reported previously. This behavior is seen even with zero-loss filtered imaging, which we believe shows that the drop in resolution is caused by elastic scattering at gas ions created by the incident electron beam. Suitable conditions for acquiring high resolution images in a gas environment are discussed. Lattice images at nitrogen pressures up to 16. mbar are shown, with 0.12. nm information transfer at 4. mbar. © 2012 Elsevier B.V. Source

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