Effects of Cr2O3 doping on the electrical properties and the temperature stabilities of PNW–PMN–PZT ceramics

The ceramics with 0.90Pb(Zr0.50Ti0.50)O3–0.07Pb(Mn1/3Nb2/3)O3–0.03Pb(Ni1/2W1/2)O3 were prepared by adding Cr2O3. The effects of Cr2O3 doping on the phase structure, the microstructure and the electrical properties of ceramics were investigated. Meanwhile, the temperature stabilities of the resonant frequency (fr) and the electromechanical coupling factor (Kp) were studied. The results showed that the better temperature stability could be obtained at x = 0.2 wt.% when the calcining temperature was 800 °C and the sintering temperature was 1150 °C. The parameters were Δfr/fr25 °C = −0.17% and ΔKp/Kp25 °C = −1.39%. Moreover, the optimized electrical properties were also achieved, which were KP = 0.54, Qm = 1730, d33 = 330 pC/N, ɛr = 2078 and tan δ = 0.0052. The optimized properties make the ceramics with this composition to be a good candidate for high power piezoelectric transformers applications.