2010 Fiscal Year Final Research Report
Fabrication of Functional Nanocrystalline Bulk Structures through Self-organization of Ceramics Nanocrystals
| Project/Area Number |
21760533
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | Gunma University (2010)
Osaka University (2009) |
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Principal Investigator |
SATO Kazuyoshi Gunma University, 大学院・工学研究科, 助教 (40437299)
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| Project Period (FY) |
2009 – 2010
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| Keywords | ナノ結晶 / 構造制御 / 集積化 / 触媒機能 |
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| Research Abstract |
Highly dispersed nanocrystals with narrow size distribution must be synthesized as a first step of fabrication of functional nanocrystalline bulk structures. We have attempt to synthesize such ceramics nanocrystals and successfully obtained nanocrystalline Y_<0.15>Zr_<0.85>O_<1.93>(YSZ),ZrO_2,TiO_2,SnO_2,CeO_2,Nb2O_5 highly dispersed in water without significant aggregation. We also challenged the control of crystalline phase and morphology of the nanocrystals, since the performance of the materials strongly depends on the structural characteristics. Consequently, we have developed a facile route for the selective growth of monoclinic and tetragonal ZrO_2 nanocrystals through surface energy control by the capping with an organic ligand, tetra-methyl ammonium (N(CH_3)_4^+). In addition, morphology controlled nanocrystals such as SnO_2 nanocubes and TiO_2 nanoribons were synthesized with similar approach. The highly dispersed nanocrystals spontaneously organized through drying and formed fibrous bulk material. The bulk material can be sintered at 500℃ and transparent polycrystalline fiber was obtained.
Another application of the nanocrystals was explored and found. The nanocrystals can be applied for nuclei of nanocomposite fabrication in co-precipitation process. The nanocrystalline (La_<0.85>Sr_<0.15>)_<0.98>MnO_3(LSM)/YSZ and NiO/YSZ composites fabricated by the method was applied for solid oxide fuel cell electrodes and demonstrated superior electrochemical performance and long-term stability.
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