Processing, structure, and electrical properties of MnO2-doped Pb(Yb1/2Nb1/2)0.10(Zr0.47Ti0.53)0.90O3 ceramics

We prepared Pb(Yb1/2Nb1/2)(0.10)(Zr0.47Ti0.53)(0.90)O-3 (PYN-PZT) piezoelectric ceramics of pure perovskite structure using the columbite precursor method with the addition of 0-0.8 wt% MnO2, and investigated in detail the effects of adding MnO2 on the sinterability, structure, and electrical properties of PYN-PZT ceramics. With a small addition of MnO2 (<= 0.5 wt%), the Mn ions are homogeneously dissolved in the PYN-PZT ceramic, leading to full densification when sintered at 1220 degrees C. However, further addition of MnO2 prevents densification, causing a high porosity and small grain size. The doping of MnO2 transforms the phase structure from tetragonal to rhombohedral. The addition of MnO2 up to a maximum of 0.5 wt% remarkably improves the mechanical quality factor (Q(m)) of PYN-PZT ceramics, simultaneously as well as maintains a high d(33) and k(p). PYN-PZT with 0.5 wt% MnO2 exhibits excellent electrical properties with d(33)=356 pC/N, k(p)=0.58, Q(m)=1215, epsilon(T)(33)/epsilon(0)=1232, tan delta=0.0035, and T-C=378 degrees C. (C) 2013 Published by Elsevier Ltd and Techna Group S.r.l.