Effects of Co 2 O 3 doping on electrical properties and dielectric relaxation of PMS–PNN–PZT ceramics

[Pb(Mn1/3Sb2/3)0.01(Ni1/3Nb2/3)0.495(Zr0.3Ti0.7)0.495O3 + x wt% Co2O3, x = 0, 0.2, 0.4, 0.6, 0.8] piezoelectric ceramics were prepared by a traditional two-step solid-state reaction method. The effects of Co2O3 doping on the phase structure, microstructure and electrical properties of the ceramics were investigated and further discussed the reasons for increase of dielectric loss and decrease of dielectric relaxation behavior. The XRD patterns show that all ceramics are pure perovskite phase structure. When doping amount of Co2O3 is 0.4 wt%, the sample exhibits the optimum properties, i.e., d33 = 768pC/N, kp = 0.63, er = 6011, tanδ = 0.008, moreover the Curie temperature (T c ) and parameter γ reach 131 °C and 1.9937, respectively. The result confirms that the ceramic is with the potentialities to be applied in low loss ceramic filter.