Ferro-/pyroelectric response of 0.57BF-0.31PMN-0.12PT ternary ceramic far away from morphotropic phase boundaries

A ternary BiFeO3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (BF-PMN-PT) solid solution with a composition far away from morphotropic phase boundaries (MPB) has been synthesized by solid-state reaction method. XRD analysis revealed a pure perovskite phase without any trace of pyrochlore phase. The system exhibited a broad phase transition with transition temperature Tc ~ 285 °C. The hysteresis loop of the ceramics displayed high remanent polarization (Pr ~ 41.23 μC/cm2) and coercive field (Ec ~ 35.41 kV/cm). The true-remanent polarization after removing the non-remanent components was evaluated by remanent hysteresis and PUND tasks, which revealed the actual usable polarization component for memory devices. Time-dependent compensated plots confirmed the resistive-leakage free characteristic of the BF-PMN-PT ceramics which makes them useful for application in devices like actuators where the electric field is switched at different rates. Fatigue test showed the ferroelectric parameters (switching and non-switching polarization values) do not vary over 107 cycles which is important especially in electromechanical transducers and memory devices. A large piezoelectric charge coefficient (d33 ~ 115 pC/N) was observed for the investigated ceramics.