[in Japanese]

View full abstract

Effect of SrTiO3 seed layer on low-temperature crystallization of Pb(Zr,Ti)O3 thin films was investigated. The PZT thin films were prepared at 290-340oC on SrTiO3 seed layers which deposited by PLD for 5-30sec at 400-600oC on (111)Pt/SiO2/(100)Si. From the TEM microstructure observation, it was found that PZT thin films deposited at 340oC consisted of amorphous and partially crystallized PZT films. It was also found that crystal orientation of SrTiO3 seed layer was changed with its deposition time and it was affected to crystal orientation of PZT film. The 5 sec of SrTiO3 deposition time showed maximum (111) intensity. Substrate heating method also affects the crystallization temperature. The induction heating reduced the crystallization temperature into 290oC and Pr=20mC/cm2, but resistive heating to 340oC and 25mC/cm2.

View full abstract

[in Japanese]

View full abstract

A ceramic thin film with a periodical hemispherical structure on a Si substrate is prepared using pulsed laser deposition (PLD) with close-packed monolayer polystyrene (PS) colloidal crystals as a template. Compared with a top-down approach such as photolithography , this method has an advantage from the point of production cost. The morphology of the film can be controlled by the geometry of the substrate in the PLD chamber. The purpose of this work is to establish a method of preparing new device application using this method.

View full abstract

[in Japanese]

View full abstract

Yttria is a promising material for application in high-power lasers, infrared windows and high temperature refractories. Transparent yttria (Y₂O₃) body was fabricated by spark plasma sintering in this study. Effects of the sintering temperature on relative density, microstructure, optical and mechanical properties of Y₂O₃ body were investigated. Highest transmittance was obtained in the Y₂O₃ body sintered at a sintering temperature of 1573 K and after annealing at 1323 K, showing a value of 55.0% and 81.7% at 550 and 2000 nm, respectively.

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

The luminescent and magnetic properties of rare-earth (RE) elements doped in insulators and metals have been thoroughly investigated, and they have been successfully applied to practically used fluorescent substances and magnets. In RE-doped semiconductors with atomic-level control, we have studied not only the exploitation of luminescent and magnetic properties but also the exploitation of new functionalities provided by their fusion. In this contribution, new development in RE-doped semiconductors, in particular Er,O-codoped GaAs with an Er-2O center, is discussed with their future prospect.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

We prepared the alkali titanium oxifluorides and alkali titanium oxides using thermal treatment by the liquid phase deposition. The preparation procedure and characterization of the deposited thin films are discussed. Highly crystallized thin film made of K₄Ti₄F₁₀O₆3H₂O was deposited on the substrate. After calcination up to 500oC, the potassium titanium oxide formed through a disproportionation reaction of titanium oxyfluoride.

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

Several LiNbO₃(LN)-type oxides with a polar structure have been synthesized by high-pressure and high-temperature heat treatment. Their crystal and electronic structures, and the physical properties such as polarity, dielectric permittivity, and magnetic susceptibility were investigated. The Goldschmidt's tolerance factor is not the only predominant factor with regards to the formation of LN-type phase and the chemical characters of constituent ions are also important. We discuss the stability, chemical bond and structure-properties relationship of LN-type oxides.

View full abstract

Structural information of specimens can be obtained in situ at high pressures and temperatures using a cubic-type multi-anvil press and synchrotron radiation x-ray diffraction measurements. Hydrogenation reaction of aluminum has been investigated via enegy dispersive and angle dispersive x-ray diffraction measurement system.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Potassium catalyst is a promising candidate for the removal of diesel particulate matter. A support is required on the filter in order to stabilize the catalyst and protect diesel particulate filter materials such as cordierite against high alkalinity derived from hydrated potassium ions. We used sodalite as the support for potassium carbonate and successfully synthesized a defect-free sodalite film on a cordierite substrate by an in situ hydrothermal treatment method. The performance of the K₂CO₃-doped film as a protection layer was investigated by SEM-EDX measurements before and after thermal treatment at 800 ^oC. An extremely small K content detected on the film-substrate interface indicates that the cordierite substrate was protected against potassium species by the obtained sodalite film.

View full abstract

[in Japanese]

View full abstract

Calcium phosphate ceramics Hydroxyapatite; HA Ca₁₀(PO₄)₆(OH)₂ are extensively used as bone or dental materials due to their high bonding ability in the living body. Besides various biomedical applications, porous HA ceramics are recently used as catalytic material. In the present study, porous HA ceramics are prepared by gel casting technique. The effect of slurry concentration on porosity, pore structure and pore morphology are investigated. Subsequently these porous bodies are used for catalytic applications. Some of the results will be presented and discussed in detail.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

The geopolymer is expected to be used as substitute materials of cement. Usually, geopolymer can been fabricated by curing materials including amorphous almonosilicate such as coal fly ash and kaolin mixed with concentrate alkaline solution. It is supposed that hardening mechanism of geopolymer would be similar to formation of natural rocks. Therefore, colored geopolymer seems to be also fabricated using a geopolymer technique. In this study, colored geopolymer was fabricated from the mixture consist of metakaolin, potassium water glass and some Cu-compounds. Chromaticity, value of copper ion, crystal phases of hardening bodies were investigated. Further, mechanical strength of the colored geopolymers were examined.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

The current Status of resources are reviewed, and the change of modarn trend of interbnational Material Flow is analysed. And, the progresses of Research on Strategic Materials are reviewed.

View full abstract

Natural processes teach us not only new scientific findings but also how to behave better for human in the future, and in easier, cheaper, and more environmentally friendly way. Therefore, studies on natural processes are excellent lessons for Earth engineering technology which is technology for human living together with the Earth. In the presentation, several examples of our lessons for Earth engineering technology, especially, sustainable remediation of contaminated water and soils and safety disposal of radioactive waste will be introduced.

View full abstract

[in Japanese]

View full abstract

Single-phase nanoparticles of brookite, a less common polymorph of TiO2 than rutile and anatase, have been successfully synthesized using a water-soluble titanium–glycolate complex as the precursor and an oleate-modified hydrothermal growth method as process. The morphology of the synthesized particles was a pseudo-cube surrounded mainly with four {210} and two {001} faces, accompanying truncation with small {111} facets. It is considered that the preferential absorption of oleate molecules on {210} and {001} resulted in such a pseudo-cube crystal shape. The obtained particles exhibited amphipathic properties possible to disperse not only in water but in nonpolar organic solvents.

View full abstract

Characterization of ferrite-based photocatalyst for advanced oxidation process was carried out in this report.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Influence of organic solvent of different solubility parameter on flow behavior of paste and screen printing process has been investigated. Ethyl cellulous and LaSrTiFeO3-delta powder were mixed with three kinds of the organic solvents of different solubility parameter to prepare the paste. A flow behavior of the paste, a film thickness and a film density depended on the organic solvent of different solubility parameter.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract