15:45 〜 16:00
▼ [18p-Z16-9] Piezoelectricity Enhancement of Textured Bi-Based Ceramics by Domain Engineering
キーワード：Bi-based, Grain-oriented, Piezoelectric strain constant
The ceramics with grain-orientation along a crystallographic direction other than that of the spontaneous polarization direction have been reported to exhibit significantly enhanced piezoelectric properties due to domain engineering. In this study, <100>-oriented 0.11(Bi0.5K0.5)TiO3-0.23BaTiO3-0.02Bi(Mg0.5Ti0.5)O3-0.64BiFeO3 piezoelectric ceramics were prepared by the reactive templated grain growth method using small and uniform plate-like particles of layered titanate; H1.08Ti1.73O4.nH2O templates, while the randomly oriented ceramics were fabricated using a solid-state reaction method. Optimum preparation conditions for the synthesis of highly <100>-oriented piezoelectric ceramics were investigated.
The reaction system with matrix component of Bi2O3, KHCO3, BaCO3, MgO, Fe2O3 exhibited the appreciable extent of <100>-orientation (F100=79.6%, which is the highest value among the BiFeO3-based grain-oriented ceramics ever reported. The presence of perovskite-structured matrix component exhibited a negligible degree of orientation (<5%). The underlying mechanism for the difficulty in texturing due to the presence of perovskite-structured matrix components was investigated by crystal structures’ and microstructures’ analysis.
The increase of piezoelectric strain constant (d33*; evaluated from unipolar S-E curves) from 295 pm/V (randomly-oriented) to 522 pm/V (77% enhancement by domain engineering) for the <100>-oriented ceramics is comparable to that of the existing lead-based systems. The large piezoelectricity with TC>400oC strongly suggested its great potentiality on replacing lead-based systems for high-temperature actuator application.
The reaction system with matrix component of Bi2O3, KHCO3, BaCO3, MgO, Fe2O3 exhibited the appreciable extent of <100>-orientation (F100=79.6%, which is the highest value among the BiFeO3-based grain-oriented ceramics ever reported. The presence of perovskite-structured matrix component exhibited a negligible degree of orientation (<5%). The underlying mechanism for the difficulty in texturing due to the presence of perovskite-structured matrix components was investigated by crystal structures’ and microstructures’ analysis.
The increase of piezoelectric strain constant (d33*; evaluated from unipolar S-E curves) from 295 pm/V (randomly-oriented) to 522 pm/V (77% enhancement by domain engineering) for the <100>-oriented ceramics is comparable to that of the existing lead-based systems. The large piezoelectricity with TC>400oC strongly suggested its great potentiality on replacing lead-based systems for high-temperature actuator application.