1988 Fiscal Year Final Research Report Summary
Investigation of the Solid State Reaction between Metallic conducting and Ferroelectric Ceramics for the Development of Materials with Extremely High Dielectric Constants
| Project/Area Number |
62470066
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機工業化学
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| Research Institution | Kyushu Insitute of Technology |
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Principal Investigator |
KUWABARA Makoto Faculty of Engineering, Kyushu Institute of Technology, 工学部, 教授 (40039136)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Hidetsugu Faculty of Engineering, Kyushu Institute of Technology, 工学部, 講師 (40037940)
HARA Yasutake Faculty of Engineering, Kyushu Institute of Technology, 工学部, 教授 (10039084)
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| Project Period (FY) |
1987 – 1988
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| Keywords | BL capacitor / Grain boundary potential barrier / Metallic conducting ceramics / Ferroelectrics / Joining of ceramics / Solid state reaction / BaPbO_3 / Pb(Fe_<2@3>,W_<1@3>)O_3 |
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| Research Abstract |
Preliminary experiments have been made in attempt to develop barrier-layer (BL) capacitors with an extremely high dielectric constant by using a metallic conducting material (BaPbO_3) and ferroelectric materials (BaTiO_2, Pb(Fe,W)O_3, and so on, which are added to form insulating grain boundary phases). Some of the experiments carried out in this study and the ob-tained results may by described as follows:
1) Solid state reaction between BaPbO_3 and TiO_2 powders: The formation of BaTiO_3 and PbTiO_3 occurred above about 800 C through the solid state reaction, and it was confirmed by X-ray diffractometry.
2) Joining of BaPbO_3 with TiO_2 ceramics and phase analysis of the reaction layers: BaPbO_3 and TiO_2 ceramics were thermally joined at 1000 C in air. It has been found that BaTiO_3 and PbTiO_3 were formed layer upon layer (side by side) at the interface between the two ceramics joined. This was confirmed by XMA (X-ray microanalysis).
3) Effect of additives on the grain structure of BaPbO_3 ceramics: More than twenty kinds of oxides were added in BaPbO_3 to examine their influences on the grain structure of BaPbO3 sintered bodies. The additions of ZnO, CuO and NiO were found to be effective to produce the materials with large grains grown favorite for making BL capacitors.
4) Preparation of SrTiO3-Pb(Fe,W)O_3 BL capacitors: BL capacitors with a high performance dielectric property have been successfully prepared using the SrTiO_3-Pb(Fe_<2/3>W_<1/3>)O_3 system. The typical dielectric constant and tan of the materials were found to be 1.5x10^5 and 5%, respectively. It may be possible to say that BL capacitors with much improved dielectric properties can be produced.
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