Thermal stability of xBiScO3–(1-x-y)PbZrO3–yPbTiO3 ternary piezoelectric system with enhanced piezoelectric and dielectric properties

Abstract

A xBiScO3–(1-x-y)PbZrO3–yPbTiO3 (denoted as xBS–(1-x-y)PZ–yPT) ternary piezoelectric system was prepared by combining BiScO3–PbTiO3 and PbZrO3–PbTiO3 for high-temperature applications. The morphotropic phase boundary region of the ternary system was identified by X-ray diffraction results together with piezoelectric and dielectric performance, which located at x = 0.054, y = 0.470; x = 0.072, y = 0.479; and x = 0.108, y = 0.492 composition intervals. Among all samples prepared, 0.072BS–0.449PZ–0.479PT displays the optimal piezoelectric and dielectric properties – piezoelectric coefficient d33 of 426 pC/N, relative dielectric constant εr of 1703, electromechanical coupling factor kp of 0.55, and Curie temperature Tc of 317°C. Additionally, this composition exhibits excellent thermal stability over a broad temperature range. Within the temperature range of 40–200°C (0.63Tc), variations in kp, mechanical quality factor Qm, and εr are 16.7% (Δkp/kp), 14.8% (ΔQm/Qm), and 5.22/°C (∂ε/∂T), respectively. The improved piezoelectric, dielectric properties and thermal stability is possibly attributed to the increasing number of irreversible non–180° domains that formed upon addition of BiScO3.