Densification and properties of oxygen sintered CuO-doped PIN-PMN-PT ceramics

Abstract

Relationships between sintering temperature and annealing atmosphere on microstructure and dielectric, ferroelectric, and piezoelectric properties of reactively sintered CuO-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ceramics were investigated. Uniform 2−3 μm grain size, dense CuO-doped PIN-PMN-PT ceramics are obtained when oxygen sintered versus a bimodal grain size microstructure when sintered in air. Oxygen sintered ceramics have excellent properties including d33 = 300–315 pC/N, EC = 7.7–8 kV/cm, and tan δ < 1.5%. The MPB region was mapped for ternary compositions doped with 0.5 mol% CuO and sintered in O2. MPB 25PIN-40PMN-35PT demonstrated the maximum piezoelectric properties with d33 = 565 +/− 23 pC/N and kp = 0.64 +/− 0.01. Sintering from 1050 °C to 1200 °C increased the coercive field from 8.5 to 11.5 kV/cm and reduced dielectric losses from tan δ = 1.8% to 0.8% by facilitating diffusion of CuO into the lattice and creating domain wall pinning defect dipoles as evidenced by an increase in the internal field bias of P-E loops.