Phase transition and thermal stability of 5.4BiScO3−(94.6-x)PbZrO3−xPbTiO3 ternary system with excellent piezoelectric properties

The 5.4BiScO 3 −(94.6- x )PbZrO 3 − x PbTiO 3 (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 5.4BiScO 3 −47.6PbZrO 3 −47.0PbTiO 3 ceramic with optimal piezoelectric coefficient d 33 of 474 pC/N, relative dielectric constant ε r of 1666, mechanical coupling factor k p of 0.64 and mechanical quality factor Q m of 415 at room temperature. Besides, the 5.4BiScO 3 −47.6PbZrO 3 −47.0PbTiO 3 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 d 33 (Δ d 33 /d 33  = 10.6%), k p (Δ k p /k p  = 14.1%), Q m (Δ Q m /Q m  = 10.3%), and ε r (∂ ε /∂ T  = 13.2/°C) at 300 °C, indicating BiScO 3 doping in PbZrO 3 −PbTiO 3 binary system could form a potential candidate for high temperature applications.