1999 Fiscal Year Final Research Report Summary
Regulation of Super Lattice Structure of Ferroelectrics by Homogeneous Precipitation Method with Polymer and Their Dielectric Property
| Project/Area Number |
10650661
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | Chiba University |
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Principal Investigator |
KAKEGAWA Kazuyuki Graduate School of Science and Technology, Chiba University, Department of Mathematics and Physical Sciences, Professor, 自然科学研究科, 教授 (50009693)
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| Co-Investigator(Kenkyū-buntansha) |
UEKAWA Naofumi Chiba University, Department of Materials Technology, Research Associate, 工学部, 助手 (60282448)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Relaxer / Pervskite Structure / Super Lattice Structure / Polyethylene Glycol / Dry Method |
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| Research Abstract |
The relaxor ferroelectrics have a broad peak on the temperature dependence of the dielectric constant due to the diffuse phase transition at the curie temperature. It is difficult to prepare the single phase of perovskite structure for the typical relaxtors such as Pb(MgィイD21/3ィエD2NbィイD22/3ィエD2)OィイD23ィエD2 (PMN), Pb(NiィイD21/3ィエD2NbィイD22/3ィエD2)OィイD23ィエD2(PNN), and Pb(ZnィイD21/3ィエD2NbィイD22/3ィエD2)OィイD23ィエD2 (PZN). The temperature dependence of the dielectric constant depends on the cation arrangement in the B site of the perovskite structure. In this study, the polyethylene glycol (PEG) was used for the preparation of the relaxers. PEG can be coordinated by the cations and can dissolve various kinds of metal salts. The PEG-cation complex was obtained the heat treatment of the PEG solution of the metal nitrate hydrate. The cation arrangement in the PEG-cation complex depended on the molecular weight of PEG. The PEG-cation complex consisted with the B site cations of the relaxers was oxidized. The oxides which contains the A site cations were mixed with the oxides obtained by the oxidation of the PEG-cation complex so that PMN, PNN, and La. Doped PMN was obtained. The relation between the cation arragement in the PEG-cation complex and the amount of the obtained perovskite phase.
When PMN was prepared by the oxidation of PEG-cation complex, the perovskite single phase was obtained at lower temperture than that the dry method was used. The formed amount of the super lattice structure in the La doped PMN increased with an increase of the molecular weight of PEG. The temperature dependence of the dielectric constant of PMN also depended on the molecular weight of PEG. The single phase of the perovskite structure of PNN was obtained by adding 1 mol% BaTiOィイD23ィエD2 and the oxidation of PEG-cation complex.
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