Excellent piezoelectric performance of Bi-compensated 0.69BiFeO3-0.31BaTiO3 lead-free piezoceramics

This work focuses on the effects of Bi compensation on the phase structure, microstructure, ferroelectric, and piezoelectric performances of new 0.69Bi1 + xFeO3-0.31BaTiO3 (x, 0–0.08) piezoceramics fabricated by traditional sintering techniques. X-ray diffraction (XRD) results indicated that Bi compensation has slight influences on the phase structure and all the ceramics locate near the morphotropic phase boundary of rhombehedral–pseudocubic phase coexistence. The rhombehedral phase fraction of all the ceramics fluctuates slightly in the range of 41.7–49.1 %. X-ray photoelectron spectroscopy (XPS) results confirmed that Bi compensation favors the decrease in the percentage of oxygen vacancy in the ceramics. An appropriate content of Bi compensation facilitates the densification, grain growth as well as enhancement of piezoelectric property of the materials. In addition, Bi compensation makes the materials “soft” along with the lower EC compared with the no compensation ceramics. Significantly, the excellent piezoelectric performance (d33 = 207 pC/N) was achieved in the 0.69Bi1.04FeO3-0.31BaTiO3 ceramics, which is higher than the results obtained in the previously reported BiFeO3-BaTiO3-based ceramics. This work would trigger further study on the BiFeO3-BaTiO3-based piezoceramics for practical application.