Phase transition and electrical properties of BiFe0.97Ga0.03O3–BaTiO3 lead-free ceramics

This investigation focuses on the phase structures, dielectric, ferroelectric and piezoelectric performances of (1−x)BiFe0.97Ga0.03O3–xBaTiO3 (x, 0.24–0.38) ceramics. A phase transition from rhombohedral to pseudocubic phase was identified as x increases. The morphotropic phase boundary (MPB) of rhombohedral–pseudocubic phase coexistence locates in a broad range of 0.26 ≤x ≤ 0.33. Particularly, both piezoelectric and ferroelectric performances of the materials near MPB were improved. For instance, high remanent polarization Pr of 23.3 μC/cm2 and piezoelectric coefficient d33 up to 173 pC/N were observed for 0.68BiFe0.97Ga0.03O3–0.32BaTiO3 ceramics. Furthermore, the ceramics near MPB has higher Curie temperature than that of the conventional Pb-based piezoceramics.