Nonlinear dielectric effect of Fe2O3-doped PMS-PZT piezoelectric ceramics for high-power applications

Piezoelectric ceramics of Pb0.98Sr0.02(Mn1/3Sb2/3)(0.05)Zr0.48Ti0.47O3 with 0.25 wt% CeO2, 0.50 wt% Yb2O3, and x wt% Fe2O3 (x = 0.02, 0.05, 0.1, 0.15, and 0.2) additives were synthesized using a conventional solid-state reaction. Their piezoelectric properties and, in particular their nonlinear dielectric behaviors were systematically investigated. Iron was mainly present in the form of Fe3+ based on X-ray photoelectron spectroscopy; a small amount of the iron was reduced to Fe2+. Iron occupied the B -site of the perovskite structure, as shown in the refinement results. The samples displayed both "soft" and "hard" properties because Fe3+ can be incorporated at the Mn2+, Zr4+, Ti4+, and Sb5+ sites. The domain wall motion was found to be related not only to the type of deficiency but also to the grain size and grain boundary effects based on the nonlinear dielectric behaviors under alternating electric fields. The optimal overall properties of d(33) = 360 pC/N, tan delta = 0.295%, Q(m) = 1500, k(p) = 0.61, epsilon(r) = 1055, alpha(epsilon) = 4.574*10(-4) m/V, and tan delta = 2.76% (under 500 V/mm) were obtained for samples sintered at 1150 degrees C(x = 0.15).