Piezoelectric materials are used in underwater sonar systems, sensors and medical imaging. Lead zirconate titanate (PZT) is one of the commercially used ceramic with the highest piezoelectric/electromechanical properties in these applications. In the literature, various lead-based or lead-free ceramic compositions have been developed and studied to be used as an alternative to PZT. Lead nickel niobate-lead zirconate titanate (Pb(Ni1/3Nb2/3)O3-Pb(Zr0.3Ti0.7)O3) (xPNN-(1-x)PZT) is one of the relaxor ferroelectric composition which has been studied to reach the higher electrical properties. 
In this study, 0.50PNN-0.50PZT and 0.55PNN-0.45PZT compositions were doped with 0.5, 1.0, and 1.5 mol% Fe, and the electrical and structural characterizations of the ceramics were carried out. All ceramic powders were fabricated by solid state reaction method. Disc-shaped ceramics were produced from the synthesized powders using a uniaxial press. The sintered ceramics were structurally characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrical characterization of all ceramics was carried out by measuring polarization-electric field (P-E) hysteresis, temperature-dependent dielectric constant and dielectric loss, and frequency-dependent admittance and phase angle. All measurement results were compared and discussed. The piezoelectric charge coefficient (d33) was measured as 705 pC/N and 590 pC/N for undoped 0.50PNN-0.50PZT and 0.5 mol% Fe doped 0.50PNN-0.50PZT, respectively.