Electrical Properties and Depolarization Temperature of (Bi1/2Na1/2)TiO3–(Bi1/2K1/2)TiO3 Lead-free Piezoelectric Ceramics
Electrical Properties and Depolarization Temperature of (Bi1/2Na1/2)TiO3–(Bi1/2K1/2)TiO3 Lead-free Piezoelectric Ceramics
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DOI：
10.1143/jjap.45.4493
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发表时间：
2006-05
影响因子：
1.5
通讯作者：
K. Yoshii;Y. Hiruma;H. Nagata;T. Takenaka
中科院分区：
文献类型：
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作者：
K. Yoshii;Y. Hiruma;H. Nagata;T. Takenaka
二元系固溶体 x(Bi1/2Na1/2)TiO3–(1-x)(Bi1/2K1/2)TiO3 [BNKT100x; x=0.50–0.98]进行了研究，重点关注去极化温度Td。无铅压电陶瓷在菱形和四方结构之间的同形相界（MPB）成分附近获得了良好的压电性能，BNKT84 的最高机电耦合系数 k33 和压电常数 d33 分别为 0.56 和 BNKT80 的 157 pC/N。然而，BNKT80 的 Td 较低（174 °C）。 MPB组合物的Td较低，且靠近MPB组合物的Td急剧下降。由于 BNKT70 具有相对较大的压电常数 d33 (126 pC/N)、动态 d33 (214 pm/V) 和高去极化温度 Td (206 °C)，因此被认为是无铅执行器应用的候选组合物。在这项研究中，我们根据介电和压电特性的温度依赖性确定了去极化温度 Td。
The piezoelectric properties of a solid solution of the binary system, x(Bi1/2Na1/2)TiO3–(1-x)(Bi1/2K1/2)TiO3 [BNKT100x; x=0.50–0.98] were investigated, focusing on depolarization temperature, Td. Fine piezoelectric properties in lead-free piezoelectric ceramics were obtained near the morphotropic phase boundary (MPB) composition between the rhombohedral and tetragonal structures, and the highest electromechanical coupling factor, k33, and piezoelectric constant, d33, were 0.56 for BNKT84 and 157 pC/N for BNKT80, respectively. However, the Td of BNKT80 was low (174 °C). The Td of the MPB composition was low, and the Td near the MPB composition was sharply decreased. It is thought that BNKT70 is a candidate composition for lead-free actuator applications owing to its relatively large piezoelectric constant, d33 (126 pC/N), dynamic d33 (214 pm/V), and high depolarization temperature, Td (206 °C). In this study, we determined depolarization temperature, Td, from the temperature dependence of dielectric and piezoelectric properties.