Enhanced piezoelectric properties of 0.55Pb(Ni1/3Nb2/3) O3-0.135PbZrO3-0.315PbTiO3 ternary ceramics by optimizing sintering temperature

0.55Pb(Ni1/3Nb2/3)O-3-0.135PbZrO(3)-0.315PbTiO(3) (PNN-PZ-PT) ternary piezoelectric ceramics with excess 1.0 wt.% PbO were synthesized by the conventional solid-state reaction method at 1175-1300 degrees C for 2 h, respectively. The influence of sintering temperature (T-s) on microstructure, piezoelectric, dielectric, and ferroelectric properties were systematically investigated. The results of XRD and Raman scattering spectra demonstrated that a typical perovskite structure with mainly rhombohedral symmetry near the MPB region were obtained for all the samples. The tetragonal phase content was increased slightly with the increase of sintering temperature. In addition, with increasing T-s the average grain size increases while the density decreases were also found. The results of electrical measurements confirmed that piezoelectric constant, dielectric constant, remnant polarization were firstly increased and then decreased with the increase of sintering temperature. The optimum and remarkable enhanced electrical properties of d(33)=1070 pC/N, k(p)=0.69, epsilon(r)= 8710, tan delta=0.026, P-r=24.08 mu C/cm(2), and E-c=3.2 kV/cm were obtained for the sample sintered at 1250 degrees C for 2 h. Meanwhile, the sample exhibits a typical relaxor ferroelectric behavior with the maximum dielectric constant epsilon(m)=24541 at Curie temperature T-c=113.3 degrees C at 1 kHz.