[20a-P6-1~6] 9.1 Dielectrics, ferroelectrics

[20a-P6-4] Fabrication and Electrical Properties of (K_0.5Bi_0.5)₂Bi₄Ti₅O₁₈ Ceramics

〇Kosuke Kuroishi¹, Hajime Nagata¹, Tadashi Takenaka¹ (1.Tokyo Univ. of Science)

Keywords:lead-free piezoelectric ceramics, bismuth layer-structured ferroelectrics, Curie temperature Tc

In this study, as one of bismuth layer structured ferroelectric[BLSF], we prepared (K_0.5Bi_0.5)₂Bi₄Ti₅O₁₈ ceramics by using KHCO₃ as the starting material and electrical properties were investigated for these ceramics. This ceramic showed high Curie temperature T_c of 533°C. A remanent polarization P_r, and coercive field E_c, were 12.2 mC/cm² and 45.5 kV/cm, respectively. This ceramic also indicated good piezoelectric properties such as piezoelectric constant d₃₃ of 18.5 pC/N and the mechanical coupling factor k₃₃ of 12.9%, respectively. Through this study, dense KBT5 could be synthesised and its electrical properties could be clarified for the first time.