Piezoelectric performance of Zr-modified lead-free BiFeO3-BaTiO3 ceramics

The structural evolution and the variation in the electrical properties of 0.67Bi1.03FeO3–0.33BaTi1-xZrxO3 (BF33BT-100xZr with x = 0.00–0.05) piezoelectric ceramics were studied. An enhanced static piezoelectric coefficient (d33) οf 248 pC/N, with a high Curie temperature (TC) of approximately 400 °C, was obtained near the morphotropic phase boundary (MPB). The room-temperature dynamic piezoelectric coefficient (d33*) was found to gradually increase from 460 to 620 pm/V as the temperature was increased to 100 °C. A large electrostrictive coefficient (Q33) of 0.018–0.032 m4/C2 in the temperature range of 25–100 °C was obtained for the BF33BT-3Zr ceramic. The enhancement of the ferroelectric and piezoelectric responses of the ceramic with increasing temperature is associated with the thermal facilitation of domain switching. A strong relationship was observed between the crystalline structure and the functional properties of the investigated ceramic series, creating a viable paradigm for future research into lead-free piezoelectric ceramics.