Excellent piezoelectric constant and thermal stability in BiScO3–PbTiO3 piezoelectric ceramics via domain engineering

The application of piezoelectric ceramics at high temperature is limited because they can't have both high piezoelectric coefficient and high Curie temperature. While, BiScO3–PbTiO3-based piezoelectric ceramics possessing high Curie temperature and piezoelectric properties simultaneously have drawn increasing attention due to their potential applications at high temperature. Here, we reported a novel compositional design of (1-x)[0.36BiScO3-0.64PbTiO3]-xBi(Sn1/3Nb2/3)O3 (abbreviated as BS-PT-xBSN). BS-PT-xBSN ceramic samples were synthesized by conventional solid state reaction method. According to the ternary phase diagram of BS-PT-xBSN ceramics brought up in this work, the morphotropic phase boundaries (MPB) were confirmed, which is located in the vicinity of x = 0.02. It canbe identified that the x = 0.02 sample near MPB has the optimal electric performance which are giant piezoelectric coefficient (d33 ∼ 450 pC/N, higher 18 % than undoped samples) and high Curie temperature (Tc ∼ 368 °C) as well as large remant polarization (Pr ∼ 46.6 μC/cm2). In addition, the variation of Pr is 3 % in the temperature range of 30–180 °C and the depolarization temperature of x = 0.02 ceramics is about 280 °C. Structural analysis such as in-situ PFM and TEM confirms that giant piezoelectricity and depolarization temperature are attributed to the appearance of nano-domain and complexity of domains as well as the stable domain configuration. This work not only reveal the high potential of BS-PT-xBSN for high-temperature piezoelectric applications but also open up a feasible approach to design new high-temperature piezoelectric ceramics.