Authors: Satoshi Wada, Tatsuya Kita, Ichiro Fujii, Kouichi Nakashima, Takahiro Takei, Nobuhiro Kumada, Toru Suzuki, Tetsuro Uchikoshi, Yoshio Sakka, Yasunari Miwa, Shinichiro Kawada, Masahiko Kimura, Yoshihiro Kuroiwa
Abstract: Barium titanate (BaTiO3, BT) grain-oriented ceramics were prepared by electrophoresis deposition (EPD) method under high magnetic field (HM-EPD) of 12 T. For this objective, the BT single-domain nanoparticles with high c/a ratio of 1.008 and size of 103 nm were prepared by two-step thermal decomposition method. Using the BT nanoparticle slurry, BT nanoparticle accumulations were prepared by EPD or slipcasting (SC) methods with/without high magnetic field. After binder burnout, these accumulations were sintered at 1350 °C and it was revealed that only the BT ceramics prepared by the HM-EPD method was assigned to grain-oriented ceramics with weak preferential crystallographic orientation along [11 direction.
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Authors: Katsuya Inaba, Ichiro Fujii, Kouichi Nakashima, Hiroshi Hayashi, Yuichi Yamamoto, Yoshihiro Kuroiwa, Satoshi Wada
Abstract: Bismuth potassium titanate ((Bi1/2K1/2)TiO3: BKT) powder were prepared using bismuth oxide (Bi2O3), potassium hydrogen carbonate (KHCO3) and titanium oxide (TiO2) raw materials. Barium titanate (BaTiO3: BT) platelike particles oriented along [110] direction were used as template particles. Barium titanate-bismuth potassium titanate (BT-BKT) ceramics had a tetragonal phase at -100 °C. The main composition was fixed to BKT 30 molar% because the Curie temperature (TC) was well above 200 °C at BKT 30 molar%. The orientation of [110]-oriented BT-BKT ceramics (BKT 30 molar%) was 54.6 %.
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Authors: Ichiro Fujii, Rintaro Mori, Kouichi Nakashima, Hiroshi Hayashi, Yoshitaka Nagamori, Yuichi Yamamoto, Tohru Suzuki, Satoshi Wada
Abstract: The piezoelectric response of [11-oriented, fine-grained BaTiO3 ceramics was investigated. It was found that an exposure of the BaTiO3 compacts to high-pressure, high-temperature steam in an autoclave promoted the orientation of the sintered ceramics. As temperature in the autoclave increased, the orientation increased. A large small-field piezoelectric constant of d33 = 517 pC/N was observed for the oriented BaTiO3 ceramics with the grain size of 1.76 μm and the Lotgering factor of 85.3 %.
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Authors: Tatsuya Kita, Shuhei Kondo, Takahiro Takei, Nobuhiro Kumada, Kouichi Nakashima, Ichiro Fujii, Satoshi Wada, Tohru Suzuki, Tetsuo Uchikoshi, Yoshio Sakka, Yasunari Miwa, Shinichiro Kawada, Masahiko Kimura
Abstract: Grain-oriented Barium titanate (BaTiO3) ceramics were prepared using an electrophoresis deposition (EPD) method under high magnetic field of 12 T and sintering at 1350 °C. It was found that BT03 and BTKK nanoparticles were necessary to synthesize the grain-oriented BT ceramics. The grain orientation was correlated with particles size and c/a ratio of lattice constants. The reason why the grain-oriented BT ceramics using the BT03 and BTKK were prepared was having the large values of the particles size and the c/a ration of lattice constants.
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Authors: Rintaro Mori, Ichiro Fujii, Hiroshi Hayashi, Yoshitaka Nagamori, Yuichi Yamamoto, Satoshi Wada
Abstract: The Barium titanate (BaTiO3, BT) [110] grain-oriented ceramics along [110] direction were prepared by a templated grain growth (TGG) method. The [110] oriented BT platelike particles (t-BT) were used as template particles. The relationship between poling treatment program and piezoelectric constant was investigated. The change in the poling conditions did not greatly influence domain size and the piezoelectric constant. The relationship between piezoelectric properties and domain size in BT grain-oriented ceramics was investigated. The smaller domain size was required to increase the piezoelectric constant.
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Authors: Wen Xiu Cheng, X.Y. He, D.Z. Sun, X.S. Zheng, P.S. Qiu
Abstract: (200) grain-oriented 0.91Pb(Zn1/3Nb2/3)O3–0.09PbTiO3 (PMN–0.09PT) piezoelectric ceramics with a degree of orientation of 0.5052 have been produced from melt by a directional solidification method. The dielectric, ferroelectric, and piezoelectric properties were investigated, e.g., ε~4200, tanδ~0.8%, d33~2100pC/N, kt~58%, and k33~90%, some of these values are comparable to those of ~PZN–PT single crystals. The strain–electric-field curve with a maximum strain of 0.49% at a field of 7kV/cm and well-saturated hysteresis loops with a Pr~32 mC/cm2 were recorded. The results demonstrate that the directional solidification method is a promising technique to fabricate high performance grain-oriented PZN–PT ceramics.
555
Authors: Rintaro Mori, Petr Pulpan, Hiroshi Hayashi, Yoshitaka Nagamori, Yuichi Yamamoto, Tetsuo Uchikoshi, Tohru S. Suzuki, Satoshi Wada
Abstract: Barium titanate (BaTiO3, BT) grain-oriented ceramics along [110] direction were prepared by a templated grain growth (TGG) method. The [110] oriented BT platelike particles (t-BT) were used as template particles. BT grain-oriented ceramics with higher relative density (Drel) over 95 %, high degree of orientation along [110] direction (F110) over 80 % and grain sizes around 30 µm were successfully prepared using only the template particles. The relationship between microstructures and piezoelectric constant (d33) was investigated. The higher F110 was, the higher Drel and the smaller grain size were required for enhancement of the piezoelectric properties.
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