Preparation of Mn-doped (Bi_0.5K_0.5)TiO₃-Bi(Mg_0.5Ti_0.5)O₃-BiFeO₃ Ceramics Using BiFeO₃ Particle Synthesized by Hydrothermal Method and Their Piezoelectric Properties

Abstract

Mn-doped 0.45(Bi_0.5K_0.5)TiO₃-0.1Bi(Mg_0.5Ti_0.5)O₃-0.45BiFeO₃ (BKT-BMT-BF) ceramics were prepared using BiFeO₃ (BF) particles synthesized by a hydrothermal synthesis as a starting material to reduce defects originating from evaporation of Bi₂O₃. X-ray diffraction patterns revealed that the synthesized BF powder and the sintered BKT-BMT-BF ceramics consisted of a single perovskite phase. The grain size of the BKT-BMT-BF ceramics was lager than that prepared by a conventional solid state synthesis. The high-field piezoelectric properties were largely improved because of de-pinning of domain walls. The remanent polarization of 24.5 μC/cm² and the apparent piezoelectric coefficient (d₃₃^*) of 268 pm/V were recorded.