Fabrication and properties of (Ba _0.85 Ca _0.15 )(Ti _0.9 Zr _0.1 )O ₃ ceramics and their multilayer piezoelectric actuators

The lead‐free ceramics with nominal composition (Ba _0.85 Ca _0.15 )(Ti _0.9 Zr _0.1 )O ₃ ( BCTZ ) were prepared by a conventional solid‐state reaction combined with a liquid precursor mixing method. Structural, dielectric, piezoelectric, and ferroelectric properties of the ceramics were systematically investigated. Excellent electrical properties of T _c ~ 101°C, tanδ ~ (0.003–0.05), k _p ~ 0.46, d ₃₃ ~ 560 pC /N, P _s ~17 μC/cm ² and a large strain of 0.43% were reproducibly obtained for the BCTZ ceramics. In addition, BCTZ ‐based monolithic multilayer piezoelectric actuators were successfully fabricated by alternately laminating the claimed piezoelectric ceramics and internal‐binder. The actuators show large displacements under low driven voltage. These results highlight that the BCTZ ceramics are excellent candidate for multilayer piezoelectric devices.