59th CEMS Colloquium

Title

New possibility of environmental high-voltage electron microscopy of nano-materials

Abstract

Various kinds of nano-materials are now in the time for application to practical use. Clarification of the dynamic process in gas and liquid circumstances is essentially important for the application in our society.

Nagoya University is one of pioneering institutes for in-situ and environmental transmission electron microscopy and diffraction of nano-materials since world-war II[1,2]

In the 1990s, our in-situ TEM observation has arrived at atomic resolution. We studied growth and stability of a small gold particle mounted on a small pillar of MgO and interaction of tips of gold like scanning tunneling microscopy using piezo-driving holders. In the 2000s, we have elucidated photo-chemical reactions on TiO₂ by in-situ HRTEM equipped with a UV illumination system.

As a fruit of these accumulated researches, Nagoya University has developed an environmental high-voltage (S)TEM equipped with an open-type environmental cell and STEM-EELS capability in 2010 [3]. This instrument opens up atomic resolution image in 100 Torr gas and some liquids.

The present talk starts with the present status of advanced TEM in comparison to X-ray diffraction/spectroscopy and moves on our environmental study of various nano-materials, which covers the results on catalytic reactions of porous gold with CO gas[4], hydrogen brittleness of composite alloys and semiconductors[5], diesel catalysts[6] and platinum reaction of carbon nanotubes (CNT) [7,8], as well as 3D observation of whole biological cells such as yeast cells[9].

As one of the future aspects, pulse-beams[10] or control of incident electrons are crucially important in coupling with laser spectroscopy onto specimens. The present author acknowledges all the collaboration people around NU, particularly Dr. S. Arai.

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4. T. Fujita et al., Nature Mater., 11(2012), 775.
5. Y. Takahashi et al., Mater. Sci. and Eng., A661(2016), 211.
6. K. Kamatani et al., Scientific Rep., 5(2015), 10161, DOI:10.1038/srep10161.
7. K. Matsuda et al., J. Appl. Phys., 120(2016), 142111.
8. K. Yoshida et al., Microscopy, 65 (2016), 1.
9. K. Murata et al., Ultramicroscopy, 146(2014), 39.
10. M. Kuwahara et al., Appl. Phys. Lett., 109 (2016), 013108.