High Power Characteristics of (Ca,Ba)TiO_3 Piezoelectric Ceramics with High Mechanical Quality Factor

摘要

(Ca_(0.1)Ba_(0.9))TiO_3 + xwt% MnCO_3 [x = 0,0.2,0.5,1.0] (CBT-Mx) ceramics were prepared by conventional sintering, and their dielectric and piezoelectric properties were measured. The mechanical quality factor (Q_m) of CBT was markedly enhanced by Mn addition and reached 2400 when x = 0.5. The dielectric loss tangent (tanδ) was 0.0023 at room temperature. The Curie temperature (T_c) was 133℃. Then, the high power characteristics of CBT-M0.5 were investigated. The maximum vibration velocity (v_0) of CBT-M0.5 was 1.1 m/s and was higher than that of Pb(Zr,Ti)O_3-based ceramics (Hard-PZT). The heat generation of CBT-M0.5 was smaller than that of Hard-PZT at the same v_0. The resonant frequency (f_r) of CBT-M0.5 was stable up to v_0 of 1.1 m/s. Additionally, the temperature stability of f_r was investigated in the practical application temperature range (from -20 to 80℃). The amount of change in f_r for CBT-M0.5 was larger than that for Hard-PZT below 10℃.