Structure evolution and enhanced electrical performance for BiScO3–Bi(Ni1/2Zr1/2)O3–PbTiO3 solid solutions near the morphotropic phase boundary

Abstract

In this work, the Bi(Me)O3–PbTiO3-type (1-x-y)BiScO3-xBi(Ni1/2Zr1/2)O3-yPbTiO3 (BS-xBNZ-yPT) ternary piezoelectric ceramics have been prepared with x ≤ 0.075 by the traditional solid-state reaction methods. For compositions with x > 0.100, the Curie temperature (Tc) will reduce below 400 °C. X-ray powder diffraction results demonstrate the system a single perovskite phase structure. Analyzed the phase structure evolutions, it can be found the MPB of this BS-xBNZ-yPT ternary solid solutions shifts to the low PT content regions with the increasing BNZ content. Dielectric diffuse behaviour in this system may result from the production of polar nanodomains by the introduction of BNZ. The piezoelectric performance is enhanced with only a little decrease in Tc by the introduction of small content BNZ. The most promising composition BS-0.025BNZ-0.635PT exhibits the piezoelectric constant d33 of 480 pC/N, planar electromechanical coupling coefficients kp of 58.2%, and Curie temperature Tc of 439 °C, respectively. The unipolar strain was found up to 0.233% with the small strain hysteresis of 11.4%. All these properties together with the good thermal stability indicate the BS-xBNZ-yPT ceramics potential candidates for high temperature piezoelectric actuator application.