Effects of Li2CO3-CuO addition on the sintering behavior, dielectric and piezoelectric properties of PZT ceramics

The influences of CuOLi2CO3 additive on the sintering behaviors, microstructure, and dielectric/piezoelectric/ferroelectric properties of a commercial soft lead zirconate titanate (PZT)-based piezoelectric ceramic have been investigated in this paper. The sintering temperature of PZT ceramic could be successfully reduced to 1050 degrees C with the addition of 0.1 wt% CuOLi2CO3. The possible sintering mechanism and sintering kinetics were studied based on the in situ measurement of temperature dependent sintering shrinkages of the samples. Some Cu/Li ions incorporated into the perovskite lattice and the remainder precipitated as Pb-rich secondary phase by eutectic formation at triple junction of grain boundaries. Cu+ seems to be more likely to enter into the perovskite lattice in comparison to Cu2+, leading to a little smaller epsilon(r), tan delta, d(33) and high temperature conduction. The addition of CuOLi2CO3 leads to an increase in the concentration of rhombohedral phase around the morphotropic phase boundary (MPB) composition, resulting in decreases in permittivity, dielectric loss, piezoelectric coefficient (d(33)), and coercive field (E-c), slight increase in remnant polarization (P-r), while little change in T-c temperature (similar to 310 degrees C) and electromechanical coupling coefficient (k(p)). Good combined dielectric and piezoelectric properties with epsilon(r) = 1881, tan delta = 1.32%, d(33) = 474 pC/N and k(p) = 0.73 could be obtained with the addition of 0.4 wt% CuOLi2CO3 after sintering at 1050 degrees C/2 h.

Automated summary

The effects of the CuOLi2CO3 additive on the sintering behavior, microstructure, and properties of a commercial soft lead zirconate titanate ceramic were studied. The addition of 0.1 wt% CuOLi2CO3 successfully reduced the sintering temperature to 1050 degrees C. Cu/Li ions incorporated into the lattice and formed secondary phases. The addition of CuOLi2CO3 resulted in changes in the concentration of phases and improved the dielectric and piezoelectric properties.