Papers by Keyword: Bismuth Potassium Titanate

Abstract: Bismuth potassium titanate ((Bi_1/2K_1/2)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 (T_C) was well above 200 °C at BKT 30 molar%. The orientation of [110]-oriented BT-BKT ceramics (BKT 30 molar%) was 54.6 %.

Abstract: Grain-oriented 0.8(Bi_1/2K_1/2)TiO₃-0.2BaTiO₃ (BKT-BT20) ceramics were prepared by the Reactive Templated Grain Growth (RTGG) method. The BKT-BT20 ceramics sintered at 1070°C for 100 h. The grain-oriented BKT-BT20 exhibited relatively high orientation factor, F, of 0.87 and density ratio of 92%. A resistivity of textured BKT-BT20 was 1.29×10¹³ Ωcm. Piezoelectric strain constant, d₃₃, and the normalized strain, d₃₃^*, of the textured BKTBT20 ceramic in the direction parallel (//) to the tape stacking direction were 117 pC/N and 243 pm/V (at 80 kV/cm), respectively.

Abstract: The piezoelectric properties of a solid solution based on the three components of bismuth sodium titanate, (Bi1/2Na1/2)TiO3 (BNT), bismuth potassium titanate, (Bi1/2K1/2)TiO3 (BKT), and barium titanate, BaTiO3 (BT), that is, x(Bi1/2Na1/2)TiO3-y(Bi1/2K1/2)TiO3-zBaTiO3 [BNBKy:z(x); x+y+z=1] are investigated. Fine piezoelectric properties in lead-free piezoelectric ceramics were obtained near the MPB composition, and the highest electromechanical coupling factors, k33 and kp, and piezoelectric constant, d33, were 0.58 and 0.36 for BNBK2:1(0.89) and 181 pC/N for BNBK2:1(0.88), respectively. In this study, we also measured the depolarization temperature, Td, from the temperature dependence of dielectric and piezoelectric properties.