Effects of Fe2O3 doping on the electrical properties of Na0.47Bi0.47Ba0.06TiO3 lead-free ceramics

摘要

The Na0.47Bi0.47Ba0.06Ti1-xFexO3-Delta lead-free piezoelectric ceramics (BNBT-100xFe, x = 0, 0.01, 0.02, 0.03) were synthesized by using the solid-state reaction technique. X-ray powder diffraction patterns demonstrate that the doping Fe2O3 has totally diffused into the crystal lattice of the ceramics and form a pure perovskite structure. Enhanced piezoelectric property is obtained at x = 0.01, which is reflected on the enhanced remnant polarization (P-r) and a giant piezoelectric constant (d(33)) up to 168 pC/N. The increasing ferroelectric-to-relaxor phase transition temperature (TF-R) on dielectric permittivity curves suggest the enhanced ferroelectric characteristics with increasing the Fe3+ content. By using the complex ac impedance analysis, the grain, grain boundary and electrode effects are all detected at the appreciate composition. The resistivity behavior of the samples is sensitive to the doping Fe3+ concentration, and additionally, the oxygen vacancies play an important role in this characteristic.