Effects of Fe2O3 doping on the microstructure and piezoelectric properties of 0.55Pb(Ni1/3Nb2/3)O3–0.45Pb(Zr0.3Ti0.7)O3 ceramics

Abstract 0.55Pb(Ni1/3Nb2/3)O3–0.45Pb(Zr0.3Ti0.7)O3(PNN–PZT) ceramics with different concentration of xFe2O3 doping (where x = 0.0, 0.8, 1.2, 1.6 mol%) were synthesized by the conventional solid state sintering technique. X-ray diffraction analysis reveals that all specimens are a pure perovskite phase without pyrochlore phase. The density and grain size of Fe-doped ceramics tend to increase slightly with increasing concentration of Fe2O3. Comparing with the undoped ceramics, the piezoelectric, ferroelectric and dielectric properties of the Fe-doped PNN–PZT specimens are significantly improved. Properties of the piezoelectric constant as high as d33 ~ 956 pC/N, the electromechanical coupling factor kp ~ 0.74, and the dielectric constant er ~ 6095 are achieved for the specimen with 1.2 mol% Fe2O3 doping sintered at 1200 °C for 2 h.