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)0.90O3 (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 °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 (Qm) of PYN–PZT ceramics, simultaneously as well as maintains a high d33 and kp. PYN-PZT with 0.5 wt% MnO2 exhibits excellent electrical properties with d33=356 pC/N, kp=0.58, Qm=1215, image/ε0=1232, tan δ=0.0035, and TC=378 °C.