| Project/Area Number |
12650327
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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 |
Electronic materials/Electric materials
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| Research Institution | Shizuoka Institute of Science and Technology |
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Principal Investigator |
OGAWA Toshio Shizuoka Institute of Science and Technology, Science and Technology, Professor, 理工学部, 教授 (40247573)
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| Project Period (FY) |
2000 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | ferroelectric Domain / Poling Field Dependence / Domain Switching / Domain Rotation / head Free Piezoelectric Ceramics / Domain Control / Pb[(Zn<1 / 3>Nb_<2 / 3>)_<0.91>Ti_<0.09>O_3 Single Crystal / Giant Electromechanical Coupling Factor of K_<31> Mode / 3)_<0.91>Ti_<0.09>O_3単結晶 / 圧電ユニモルフ / 圧電バイモルフ / 振動モード解析 / 周波数定数 / 結晶異方性 / 単斜相系 / リラクサ強誘電体単結晶 / 3>)_<0.91>Ti_<0.09>]O_3 / 巨大電気機械結合係数k_<31> / モノドメイン / ドメイン構造 / バイポーラパルス分極 / P-Eヒステリシス曲線 / ビスマス層状化合物セラミックス / リラクサ強誘導電体単結晶 / ドメインクランピング / 抗電界 / 巨大圧電d_<31>定数 / チタン酸鉛セラミックス / チタン酸バリウムセラミックス / PZTセラミックス / 結晶配向度 / 90°ドメイン回転 |
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| Research Abstract |
(1)Domain behavior of ferroelectric materials was investigated by a poling field (E). Ferroelectric materials evaluated consist of lead zirconate titanate (PZT), lead titanate (PT), barium titanate (BT), Bi-layer structured SrBi_4Ti_4O_<15> (SBT) ceramics and Pb(Zn<1/3>Nb_<2/3>)_<0.91>Ti_<0.09>O_3 (PZNT91/09) single crystal. Changing the poling field (E) from 0→+E→0→E→0 to +E, the electromechanical coupling factor (k), dielectric constant (εr) and frequency constant (fc) were measured. The minimum k and εr were obtained at the same E because of the 180゜ domain clamping. The E due to the domain clamping corresponded to the coercive field (Ec) determined by the poling field dependences. At the Ec, maximum fc was confirmed in the cases of soft PZT (tetragonal and rhombohedral), hard PZT (tetragonal), BT ceramics and PZNT91/09 single crystal. It was thought that the materials became mechanically hard by the electrical attracting through the domain clamping. In hard PZT (rhombohedral), PT, BT and SBT ceramics, the peak of εr and minimum fc were observed at an E, which corresponds to the threshold of domain rotations. At the E, the ceramics become mechanically soft because of the domain rotations.
(2)The giant electromechanical coupling factor of k_<31> mode over 80% had been found by realizing the mono-domain in the case of PZNT91/09 single crystal plates. From the investigation of the fc which corresponds to a half of the bulk wave velocity, the giant k_<31> appeared in the case of the phase with low crystal symmetry in comparison with tetragonal phase.
(3)Piezoelectric bimorphs were prepared to utilize the giant k_<31>. The PZNT91/09 single crystal bimorph showed the superior piezoelectric properties such as three orders of magnitude larger than the PZT ceramic bimorph regarding the impedance ratio on the resonant and the anti-resonant frequencies.
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