Enhanced performance by inducing defect dipoles in lead based relaxor ferroelectric PHT-based ceramics

Mn-doped 0.49 Pb(Ni1/3Nb2/3)O-3-0.51 Pb(Hf0.3Ti0.7)O-3 (abbreviated PNN-PHT) ceramics were prepared by solid-phase reaction method. The influence of defect dipoles on various properties was systematically studied. Results showed that Mn doping significantly improved mechanical quality factor Q(m) of PNN-PHT ceramics and greatly reduced dielectric loss, while Curie temperature T-c was also slightly increased. After 10(5) electric field cycles, Mn doped PNN-PHT ceramic showed excellent fatigue property. Based on ferroelectric and dielectric properties of samples, the reason for defect dipole and internal mechanism of its influence on piezoelectric properties were elucidated. Finally, novel ceramic 0.75 mol% Mn-doped PNN-PHT with excellent performance was obtained (d(33)similar to 750 pC/N, k(p)similar to 0.55, Q(m)similar to 384 and tan delta similar to 0.59%). Therefore, results of this work suggest that these ceramics may be potential candidates for piezoelectric actuators and high-power devices.