A Pb(In1/2Nb1/2)O3–Pb(Zn1/3Nb2/3)O3–PbTiO3 ternary ferroelectric system with high TC and high piezoelectric properties

(0.79 − x)Pb(In1/2Nb1/2)O3–0.21Pb(Zn1/3Nb2/3)O3–xPbTiO3 (x = 0.23–0.35) ternary ferroelectric system in the form of ceramics have been synthesized. Its structure and properties have been studied by X-ray powder diffraction and electric measurements. A morphotropic phase boundary region has been determined in the composition range of 0.28 < x < 0.32, where the Curie temperature TC and the rhombohedral–tetragonal phase transition temperature TRT were found to vary from 243 °C to 295 °C and 145 °C to 191 °C, respectively, much higher than PMNT and PZNT systems. The compositions within MPB region exhibit excellent piezoelectric properties such as piezoelectric coefficient d33 > 646 pC/N, TRT > 145 °C, TC > 273 °C and EC > 13 kV/cm for 0.5PIN–0.21PZN–0.29PT and 0.49PIN–0.21PZN–0.30PT, making the ceramics of this system a promising material for high power and high temperature application.