Bipolar and Unipolar Fatigue of Ferroelectric BNT-Based Lead-Free Piezoceramics

The bipolar and unipolar fatigue behavior of the lead-free piezo- and ferroelectric 0.94Bi1/2Na1/2TiO3–0.06BaTiO3 (94BNT–6BT) was investigated. To obtain a complete profile of the fatigue behavior, both large-signal (polarization, strain) and small-signal (d33, ɛ33) properties were measured at room temperature. The results indicate that the material suffers a significant degradation in both large- and small-signal properties after cycling, with most of the fatigue occurring in the first 104 cycles of the fatigue test