Electrical Properties and Depolarization Temperature of (Bi1/2Na1/2)TiO3–(Bi1/2K1/2)TiO3 Lead-free Piezoelectric Ceramics

概要

論文の詳細を見る
The piezoelectric properties of a solid solution of the binary system, $x$(Bi1/2Na1/2)TiO3–($1-x$)(Bi1/2K1/2)TiO3 [BNKT100$x$; $x=0.50--0.98$] were investigated, focusing on depolarization temperature, $T_{\text{d}}$. 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, $k_{33}$, and piezoelectric constant, $d_{33}$, were 0.56 for BNKT84 and 157 pC/N for BNKT80, respectively. However, the $T_{\text{d}}$ of BNKT80 was low (174 °C). The $T_{\text{d}}$ of the MPB composition was low, and the $T_{\text{d}}$ 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, $d_{33}$ (126 pC/N), dynamic $d_{33}$ (214 pm/V), and high depolarization temperature, $T_{\text{d}}$ (206 °C). In this study, we determined depolarization temperature, $T_{\text{d}}$, from the temperature dependence of dielectric and piezoelectric properties.
Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physicsの論文
2006-05-30