Enhanced electromechanical properties in MnCO3-modified Pb(Ni,Nb)O-3-PbZrO3-PbTiO3 ceramics via defect and domain engineering

The development of piezoelectric ceramics with both large piezoelectric responses and mechanical quality factor is still a key challenge for practical applications for high-power piezoelectric devices. Here we report the strategy to utilize the synergistic contribution of engineered defect and domain structure, in which an excellent piezoelectric coefficient d(33) of 655 pC N-1 and mechanical quality factor Q(m) of 371 are simultaneously achieved in MnCO3-modified Pb(Ni,Nb)O-3-PbZrO3-PbTiO3 (Mn-PNN-PZ-PT) ceramics. Meanwhile, the depolarization temperature (T-d) and the temperature corresponding to the epsilon(r,max) (T-m) are enhanced relative to the pure counterpart. After annealing at 90 degrees C, the sample with x = 0.3 shows the retained d(33) value of 610 pC N-1, about 2.6 times larger than that with x = 0 counterpart, demonstrating a wider operating temperature range. These enhanced electromechanical properties originate from the internal bias field introduced by the defect dipoles (MnZr,Ti ''-VO center dot center dot)X${{\rm{(Mn}}_{{\rm{Zr,Ti}}}<^>{\prime\prime} - V_{\rm{O}}<^>{{\rm{ \bullet \bullet }}}{\rm{)}}}<^>X$ and (MnNb '''-VO center dot center dot)'${{\rm{(Mn}}_{{\rm{Nb}}}<^>{{\rm{\prime\prime\prime}}} - V_{\rm{O}}<^>{{\rm{ \bullet \bullet }}}{\rm{)}}}<^>{\rm{\prime}}$. It is verified that xMn-PNN-PZ-PT ceramics have superior potential for high-power application, meanwhile, paves a significant step toward enhancing the thermal stability of high-temperature piezoceramics.