Authorized Personnel Only


Department of Materials Science and Engineering,
Graduate School of Science and Technology,
Kumamoto University
2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan



Research outlines

Research details

 Research interests is the structural control of carbon or oxides by chemistry, and the fabrication of functionalized their devices. The methods of structural control are 1. Chemical vapor deposition (CVD), 2. Anodization of metal sheet, and 3. Hydrothermal synthesis under inert atmosphere.

  1. Chemical vapor deposition (CVD): carbon nanotubes (CNTs) prepared by CVD. The three kinds of CNTs are synthesized by optimization of gas composition, gas pressure, gas flow rate, and atmospheric temperature, which have carbon nanofibers (CNFs) mat, CNTs grown radically, and CNTs arrays.
  2. Anodization of metal sheet: the high voltage of several tens is applied to the metal sheets such as aluminum or titanium immersed as an anode electrode in electrolyte solution, leading to formation of nanohole arrays or nanotube arrays as oxidation films by oxidation of metal sheets as an anode. This phenomena can be useful for self-organization of oxide nanostructure.
  3. Hydrothermal synthesis: the inner pressure becomes ca. 1 MPa by boiled water when the mixture of hydrogel such as tin hydrate and ammonia aqueous solution is hold at ca. 200 degree C for 24 h in the vessel sealed by Teflon. This pressure acts as chemical reaction, i.e., nano-sized interaction, inducing the formation of nano-structure such as semiconductor materials: tungsten oxides, tin oxides, and barium titanate.

 The structural characterization techniques of above-mentioned nanomaterials are X-ray diffraction (XRD) and electron diffraction by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and scanning tunnel microscopy (STM), and spectroscopic methods such as Raman, X-ray photon spectroscopy (XPS) and X-ray absorption fine structure (XAFS).
 The application properties of nanomaterials are widely evaluated as gas detection, catalytic reaction, and positive coefficient (PTC) and so on. The device properties of nanomaterials are examined as the micro/nano interdigitated metal electrodes fabricated micro-electro machining system (MEMS) such as ultra-violet photolithography, focus ion beam, and etc. in micro-system technical development center.

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