Effects of Cr2O3 doping on the electrical properties and the temperature stabilities of PZT binary piezoelectric ceramics

The ceramics with Pb1.04Zr0.52Ti0.48O3 + z wt.% Cr2O3 were prepared using the traditional technique. 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) were studied. The results showed that the Δfr/fr,25°C decreased with the addition of 0.2 wt.% −0.8 wt.% Cr2O3 as compared with the undoped samples. The minimum value (−0(−0.182%) of Δfr/fr,25°C was obtained for z = 0.6 wt.% Cr2O3 samples that sintered at 1260°C. The values of ɛT33/ɛ0 = 1650, tanΔ = 0.006, d33 = 328 pC/N, Kp = 0.63, Qm = 2300 were obtained when Cr2O3 was 0.6 wt.%, which exhibited more excellent piezoelectric properties than other compositions such as those with z = 0.2 wt.%, 0.4 wt.%, and 0.8 wt.%, but had a similar value as compared with the undoped samples. When the Cr2O3 additive increased, the Curie temperature moved toward low temperature and the changes of resonant frequency changed from positive to negative with increasing temperature.