Selectively designed Fe doping of lead-free BaTiO3 piezoceramics.

Fe doping has been investigated to determine the effect of defects on the piezoelectric properties of BaTiO₃ ceramics. Fe doping can produce oxygen vacancies due to ionic replacement, and then a defect dipole ( Fe Ti ′ - V O · · ) is formed. This acceptor characteristic typically induces a reduced piezoelectric constant but improves the thermal stability and fatigue behavior. A thermally stimulated depolarization current (TSDC) is employed to distinguish the role of defect dipoles from oxygen vacancies and characterize the reasons for fatigue behavior and thermal stability. TSDC of the pure BaTiO₃ ceramic shows one peak, whereas Fe-doped ceramic shows two peaks. The first and second peaks are presumably ascribed to defect dipole and space charge polarization, respectively. This study provides an effective method to extensively investigate the effect of defect configuration on ferroelectric–piezoelectric behavior. [ABSTRACT FROM AUTHOR]