Yasunari Miwa

Preparation of Barium Titanate Grain-Oriented Ceramics by Electrophoresis Deposition Method under High Magnetic Field Using Single-Domain Nanoparticles

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.

Processing and enhanced piezoelectric properties of highly oriented compositionally modified Pb(Zr,Ti)O3 ceramics fabricated by magnetic alignment

Highly oriented compositionally modified Pb(Zr,Ti)O3 (PZT) ceramics were successfully obtained by slip casting in a high magnetic field. PZT is a well-known superior ceramic with the highest piezoelectric properties, and these properties have been expected to be further improved through crystalline orientation. However, highly oriented PZT ceramics fabricated by slip casting in a high magnetic field have never been reported. We obtained oriented ceramics using compositionally modified PZT with Pb(Ni,Nb)O3, and their Lotgering factor was 0.77. The electromechanical coupling coefficient (k31) increased by 30%, and an extremely high value of 0.44 was achieved for the oriented ceramics.

Textured PbTiO3 Based Ceramics Fabricated by Slip Casting in a High Magnetic Field

Textured PbTiO3 (PT) ceramics were fabricated by slip casting in a high magnetic field of 12 T. The sample obtained from the powder calcined at 1100 °C was (100), (010), and (001)-oriented, and the orientation factor was 90 %. On the other hand, the sample obtained from the powder calcined at 900 °C was not oriented. Aggregability and crystallinity of powder are an important factor when textured ceramics are fabricated by slip casting in a high magnetic field.

Preparation and Characterization of Grain-Oriented Barium Titanate Ceramics Using Electrophoresis Deposition Method under a High Magnetic Field

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.

Preparation and characterization of Grain-Oriented Barium Titanate Ceramics Using Electrophoresis Deposition Method under A High Magnetic Field

Barium titanate (BaTiO3) grain-oriented ceramics were prepared using electrophoresis deposition (EPD) method under high magnetic field of 12 T. First, BaTiO3 nanoparticles with high c/a ratio of 1.008 and size of 84 nm were prepared by two-step thermal decomposition method with barium titanyl oxalate nanoparticles. Using the BaTiO3 slurry, BaTiO3 nanoparticle accumulations were prepared by EPD method under high magnetic field. After binder burnout, the accumulations were sintered and BaTiO3 grain-oriented ceramics were prepared. Moreover, dielectric properties of their ceramics were investigated