[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Dense mesoporous alumina bulks were successfully synthesized by a hydrothermal hot-pressing (HHP) method. First, mesoporous alumina was prepared as starting material which possesses a high BET surface area and narrow pore size distribution. Mesoporous alumina bulks prepared by hydrothermal hot-pressing (HHP) had high density with uniformity pore size distribution and a high specific surface area. Their features for dense mesoporous alumina bulks were observed by SEM and mesopores were evaluated by XRD, N2 adsorption/desorption technique, TEM and humidity conditioning property.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

It is necessary to develop high-performance engieering plastics. In order to promote its development, addition of ceramic filler is a key. In this work, we prepared high thermal conductivity filler and evaluated its properties. The developed filler was then addded the engineering plastics.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Face centered cubic (fcc) single crystal silver nanoparticles(NPs) of nearly monodispersed particle size of 12nm were prepared by simple ripening multi-twined particles (MTP). The product yield was nearly 100% and growth mechanism was considered to utilize chemical potential difference between MTP and fcc NPs. Particle size after ripening process was able to be controled with MTP/FCC ratio before ripening, but did not depend upon the ripening temperature. Numerical ratio of MTP/FCC before ripening depened upon deposition temperature or heating rate of raw material for Ag nanoparticle generation, and considered to be affected by kinetic effects. By this method, it was possible to control Ag nanoparticle size only by controling particle generation process,

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Nano-grains of LiNbO₃ have been synthesized from Li-Nb ethoxide by sol-crystal method. Structural characterization of specimens annealed at various temperatures was performed by transmission electron microscopy (TEM) and X-ray difractometory (XRD). The single crystal of Li-Nb ethoxide was decomposed to an amorphous matrix below 473 K. XRD data showed that small crystals were grown by heating above 673 K, and the crystal sizes became larger with increasing temperature. TEM data showed that the small crystalline phase was formed in the amorphous matrix at 553 K and the crystal region was expanded by an irradiation electron beam. The crystallization and grain growth process were successfully observed in-situ by high-temperature TEM. We discuss the crystallization process of LiNbO3 and compared with NaNbO₃ and (Li,Na)NbO₃.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Ag-colloid and/or AgX-colloid dispersed organosilsesquioxane-titania films were prepared via sol-gel method, and the coloration and bleaching behavior of the films with UV-irradiation and heat treatment was investigated. The redox of Ag+/Ag in the hybrid films was changed significantly by changing the functional groups of organosilsesquioxanes and by the amounts of TiO2 component.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Aluminum oxide (Al2O3) has thermally and chemically stable property and is widely used as insulating ceramics materials. Recently, it has attracted much attention as insulating layers of Metal-Oxide Semiconductor Field-Effect Transistor (MOSFET), Tunnel Magneto-Resistance (TMR) devices and so on. Previously we reported low temperature epitaxial growth of Al2O3 films using the electron-beam induced process. This method allows us to control artificially the crystallinity of Al2O3 films. In this work, by using this electron-beam induced process and hydrogen-reduction technique, we attempted to fabricate epitaxial oxide/metal hybrid systems.

View full abstract

Oriented hexagonal B-C-N films were synthesized on HOPG by RF-PECVD using Tris(dimethylamino)borane as a precursor. The films were characterized by XPS and NEXAFS measurements. The XPS measurements showed that B atoms bonded to C and N atoms to form the B-C-N atomic hybrids and the atomic ratios of B, C and N were almost unity. The NEXAFS spectra of the B K-edge had the peaks due to pi* and sigma* resonance of sp2 hybrid orbitals implying the existence of sp2 hybrid configuration of B-C-N bonds around the B atoms. The orientation of the B-C-N sheets as promoted by heat-treatment up to 900oC was confirmed by the polarization-dependence of NEXAFS.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Ultrathin layers of positively charged poly(diallyldimethylammonium chloride) (PDDA) and negatively charged poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) were alternately deposited on negatively charged phenylsilsesquioxane (PhSiO_3/2) particles via layer-by-layer assembly technique. A monolithic sheet-electrolyte was successfully obtained from the PAMPS-deposited PhSiO_3/2 particles by pressing at 70 MPa.Proton conductivity of the sheet composed of PAMPS-deposited particles is discussed relating to the core particles size.

View full abstract

The membrane for intermediate temperature fuel cell was fabricated by using grycidoxypropyl-methyl-diethoxysilane and histidine and zirconium phosphate. The ionic conductivity of the membrane was measured at 160 ºC without any humidification. The conductivity was estimated to be 4.7×10^-9 S/cm. The fabricated membrane is expected to be an alternative membrane for the PEFC operated under intermediated temperature without humidification by improving the conductivity, though the conductivity was not high enough for practical use in fuel cell at the moment.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Transition metal Layered oxides as the 1st generation cathodes for Lithium-ion batteries have some key issues such as safety, environmental impact and cost. To overcome the intrinsic problems, iron-based corner shared polyanionic cathodes have been investigated. Phospho-olivine as the 2nd generation cathodes and post-olivine as the next generation cathodes will be introduced.

View full abstract

As a cathode active material for Li ion battery, LiCoO2 is the most widely used. Because the Co is high cost, researches on alternative materials have been advanced. In this work, we focused on the spinel-type LiMn2O4. During charge-discharge cycles, however, the capacity of the LiMn2O4 decreases, especially at elevated temperatures, and this deterioration is considered due to dissolution of the Mn into electrolyte. Previously we found that supersonic-wave treatment in Zn-coating solution made electrode property of the LiMn2O4 better. In this work, we try to improve the electrode property by supersonic-wave treatments using Ni or Mg aqueous solution.

View full abstract

[in Japanese]

View full abstract

The electrical conductivity of lithium borohydride (LiBH4) measured by the ac complex impedance method increased by three orders of magnitude due to structural transition from orthorhombic to hexagonal at approximately 390 K. Spin-lattice relaxation time (T1) of 7Li nuclear magnetic resonance (NMR) was in good agreement with the measured electrical conductivity.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract