Phase Transition and Thermal Stability of 5.4Bisco3−(94.6-X)pbzro3−xpbtio3 Ternary System with Excellent Piezoelectric Properties

The 5.4BiScO3−(94.6-x)PbZrO3−xPbTiO3 (43.0 < x < 51.0 mol%) ternary piezoelectric ceramics were synthesized by solid-state reaction method. Phase transition from rhombohedral to tetragonal structure was identified by X-ray diffraction. In combination with piezoelectric and dielectric properties, the morphotropic phase boundary (MPB) composition was confirmed in 5.4BiScO3−47.6PbZrO3−47.0PbTiO3 ceramic with optimal piezoelectric coefficient d33 of 474 pC/N, relative dielectric constant εr of 1666, mechanical coupling factor kp of 0.64 and mechanical quality factor Qm of 415 at room temperature. Besides, the 5.4BiScO3−47.6PbZrO3−47.0PbTiO3 ceramic retained most of the piezoelectric properties in broad temperature range between 40 and 300 °C, which exhibited excellent thermal stability. There were only gentle variations in d33 (Δd33/d33 = 10.6%), kp (Δkp/kp = 14.1%), Qm (ΔQm/Qm = 10.3%), and εr (∂ε/∂T = 13.2/°C) at 300 °C, indicating BiScO3 doping in PbZrO3−PbTiO3 binary system could form a potential candidate for high temperature applications.