09:30 〜 11:30
▼ [10a-PA4-3] Fabrication of textured BNT-based green body with high magnetic field electrophoretic deposition (HM-EPD)
キーワード：texture technique, lead-free piezoelectric, electrophoretic deposition
Lead-free piezoelectric materials have been attracting attention because the most of the countries have made an effort to eliminate lead contents from commercial products. However, lead-based piezoelectric materials are still in use because of the poor piezoelectric properties in current lead-free piezoelectric materials. For example, [001]-Pb(Zn, Nb)O3-PbTiO3 (PZN-PT) single crystal has the highest piezoelectric constant (d33) over 2,000 pC/N due to engineered domain configuration.
Among of lead-free piezoelectric materials, (Bi0.5Na0.5)TiO3 (BNT) based piezoelectric ceramic is already used in real application, however, it has low piezoelectric constant about 110 pC/N. Therefore, to enhance piezoelectric performance, it is considered application of engineered domain configuration in BNT-based piezoelectric materials. In literature, to apply engineered domain configuration in BNT based ceramic, textured and fine-grained structure are required. To achieve above conditions, we have investigated high magnetic field electrophoretic deposition (HM-EPD) method in BNT-based material. In HM-EPD method, a particle should have large diamagnetic anisotropy (Δχ) and it is related to crystal anisotropy. It was reported that textured hexagonal BT green body was successfully fabricated with HM-EPD method due to its large c/a ratio = 2.44. In this case, there is advantage that orientation seed can be used large c/a ratio particles without plate-like shape of particle.
In this work, to obtain highly oriented BNT-based green body with HM-EPD method, it was conducted with suspension consisted of BNT and orientation seed with large c/a ratio. After then, we evaluated orientation factor in fabricated green body using Lotgering factor (F001) from XRD patterns. Detailed experimental results will be provided during presentation.
Among of lead-free piezoelectric materials, (Bi0.5Na0.5)TiO3 (BNT) based piezoelectric ceramic is already used in real application, however, it has low piezoelectric constant about 110 pC/N. Therefore, to enhance piezoelectric performance, it is considered application of engineered domain configuration in BNT-based piezoelectric materials. In literature, to apply engineered domain configuration in BNT based ceramic, textured and fine-grained structure are required. To achieve above conditions, we have investigated high magnetic field electrophoretic deposition (HM-EPD) method in BNT-based material. In HM-EPD method, a particle should have large diamagnetic anisotropy (Δχ) and it is related to crystal anisotropy. It was reported that textured hexagonal BT green body was successfully fabricated with HM-EPD method due to its large c/a ratio = 2.44. In this case, there is advantage that orientation seed can be used large c/a ratio particles without plate-like shape of particle.
In this work, to obtain highly oriented BNT-based green body with HM-EPD method, it was conducted with suspension consisted of BNT and orientation seed with large c/a ratio. After then, we evaluated orientation factor in fabricated green body using Lotgering factor (F001) from XRD patterns. Detailed experimental results will be provided during presentation.