[8a-F212-1~11] 9.1 Dielectrics, ferroelectrics

9:00 AM - 9:15 AM JST(12:00 AM - 12:15 AM UTC)

[8a-F212-1] Relaxor–Ferroelectric Phase Transformation and Giant Ferroelectric/Piezoelectric Responses in (Bi_0.5K_0.5)TiO₃ Ceramics

〇Desheng Fu^1,2,3, Yoshiki Saito², Daichi Watanabe¹ (1.Fac. Eng. Shizuoka Univ ., 2.GSIST, Shizuoka Univ., 3.GSST, Shizuoka Univ.)

Keywords:

piezoelectric,(Bi0.5K0.5)TiO3,ferroelectric

(Bi_0.5K_0.5)TiO₃ (BKT) has attracted considerable attention as a lead-free piezoelectric material capable of operating at elevated temperatures. However, owing to the high volatility of Bi and K, the fabrication of dense BKT ceramics is challenging, and its physical properties remain insufficiently understood. In this study, highly dense BKT ceramics were prepared by spark plasma sintering (SPS), and the effects of annealing conditions on their structure and electrical properties were investigated. A relaxor-to-ferroelectric phase transformation induced by annealing was identified. Samples with well-developed ferroelectricity exhibited a large remanent polarization of 42 μC/cm² and an electric-field-induced strain of 0.29%. These results demonstrate that the formation of the ferroelectric phase plays a crucial role in enhancing the piezoelectric response of BKT ceramics.