Effect of MnO2 on the microstructure and electrical properties of 0.83Pb(Zr0.5Ti0.5)O3-0.11Pb(Zn1/3Nb2/3)O3-0.06Pb(Ni1/3Nb2/3)O3 piezoelectric ceramics

A sample of 0.83Pb(Zr0.5Ti0.5)O-3-0.11Pb(Zn1/3Nb2/3)O-3-0.06Pb(Ni1/3Nb2/3)O-3 (PZNNT) to which MnO2 was added, with a high mechanical quality factor (Q(m)) and a good transduction coefficient (d(33) x g(33)), were systematically investigated. Based on the SEM analysis there existed two kinds of secondary phases, Rich Ti and Rich Zn phases, which arose due to the B-site substation of PZNNT-based ceramics by manganese ions. One phase was due to the Mn3+ replacing the Ti4+ to create oxygen vacancies and induce the hardening effect. Another phase was due to the Mn2+ replacing the Zn-site to stabilize the perovskite phase. When the addition of MnO2 reached the solubility limit of 1.5 mol% in the PZNNT-based ceramics, the sample showed optimal electrical properties (Q(m) = 357, d(33) x g(33) = 9859 x 10(-15) m(2)/N, k(p) = 0.56), which suggested its potential application for piezoelectric energy harvesting in larger field excitation environments.