Piezoelectric Properties of (Bi1/2Na1/2)TiO3-Based Solid Solution for Lead-Free High-Power Applications

概要

論文の詳細を見る
Lead-free piezoelectric ceramics based on $x$(Bi1/2Na1/2)TiO3–$y$(Bi1/2Li1/2)TiO3–$z$(Bi1/2K1/2)TiO3 [$x + y + z = 1$] (abbreviated as BNLKT100$y$-100$z$) were prepared by conventional ceramic fabrication process. In this study, we clarified that the mechanical quality factor $Q_{\text{m}}$ of the rhombohedral side of the MPB composition is rather superior to that of the tetragonal side, although the piezoelectric constant $d_{33}$ of the rhombohedral side is lower than that of the tetragonal side and MPB composition. As a second work, the effects of Mn doping on the variations in $T_{\text{d}}$ and piezoelectric properties including high-power characteristics were investigated using BNLKT4-8, which is a rhombohedral composition. The $Q_{\text{m}}$ of $w$ wt % MnCO3-doped BNLKT4-8 (abbreviated as BNLKT4-8Mn$w$) markedly increased with increasing Mn concentration $w$, while $T_{\text{d}}$, coupling factor $k_{33}$, and $d_{33}$ slightly decreased. The high-power characteristics of BNLKT4-8Mn0.6 were superior to those of hard PZT at a vibration velocity $v_{\text{0--p}} > 0.6$ m/s. Therefore, a Mn-doped BNT-based solid solution with rhombohedral symmetry is a promising candidate for lead-free high-power applications.
Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physicsの論文
2008-09-25