Preparation and characterization of Pb(Lu1/2Nb1/2)O3-Pb(Ni1/3Nb2/3)O3-PbTiO3 ternary ferroelectric ceramics with high piezoelectric constant

Pb(Lu1/2Nb1/2)O3-Pb(Ni1/3Nb2/3)O3-PbTiO3 ferroelectric ceramics were successfully prepared by a modified two-step columbite precursor method. The structural, dielectric, ferroelectric and piezoelectric properties were characterized by X-ray diffraction, ferroelectric and dielectric measurements. All the obtained samples have pure perovskite structure. The composition of 0.17PLN-0.47PNN-0.36PT within morphotropic phase boundary exhibits optimal properties with piezoelectric coefficient d33 = 378 pC/N, Curie temperature Tc = 142 °C, dielectric constant ε΄ = 4700, dielectric loss tangent tanδ = 0.05, remnant polarization Pr = 27.1 μC/cm2 and coercive field Ec = 8.89 KV/cm. According to Curie-Weiss Law and Lorentz-type quadratic relationship, the dielectric behavior was studied and the relaxor factor γ is between 1.55–1.87, indicating the character of diffuse phase transition of the Pb(Lu1/2Nb1/2)O3-Pb(Ni1/3Nb2/3)O3-PbTiO3 ceramics. The excellent piezoelectric properties and high Curie temperature make this system a promising material for high-power transducer applications in a broad temperature range.