Structure and ferroelectric properties in (K0.5Bi0.5)TiO3–BiScO3–PbTiO3 piezoelectric ceramic system

(K0.5Bi0.5)TiO3–BiScO3–PbTiO3 ceramics were synthesized by conventional solid-state method. A morphotropic phase boundary (MPB) was confirmed with the aid of structural analysis. Two dielectric anomalous peaks were observed, the one around dielectric maximum temperature (Tm) due to phase transformation from ferroelectric to paraelectric while the second one could be ascribed to space charges. Furthermore, the existence of space charges also resulted in the independence of Tm with frequency at low lead composition. A new high temperature piezoelectric ceramic, 0.30(K0.5Bi0.5)TiO3–0.30BiScO3–0.40PbTiO3 close to MPB exhibited excellent electrical properties with Tm of 384 °C, d33 of 247 pC/N, kp of 38.9%, Pr of 19.41 μC/cm2, and Ec of 2.25 kV/mm, indicative of a candidate for high temperature application.