Achieving both high d ₃₃ and High Q _m for the Pb(Zr_0.26Sn_0.26Ti_0.48)_1-x Fe _x O_3-x/2 ternary system for use in high-power ultrasonic transducers

For applications in high power ultrasonic transducers, both high piezoelectric coefficients d ₃₃ and high mechanical quality factor Q _m are essential. In this work, acceptor-doped Pb(Zr_0.26Sn_0.26Ti_0.48)_1-x Fe _x O_3-x/2 ferroelectric ceramics with compositions near the morphotropic phase boundary were prepared by routine solid-state reaction. By introducing Fe³⁺ ion into the perovskite crystal lattices, defect dipoles resulting from Fe³⁺ ions and oxygen vacancies are formed, pinning extrinsic domain wall motion, and hence increasing Q _m but reducing d ₃₃. It was found that substitution with 0.5 mol% Fe³⁺ resulted in high d ₃₃ (390 pC/N) and high Q _m (540). The nonlinear dielectric responses of these ceramics were evaluated on the basis of the Rayleigh law. Both Rayleigh coefficients,\alphaα and\kappa-{\rm{init}},κ init, are reduced by doping with the acceptor ion Fe³⁺, indicating that the intrinsic contribution and reversible domain wall mobility are both reduced.