Enhanced piezoelectric strain of BiFeO3–Ba(Zr0.02Ti0.98)O3 lead‐free ceramics near the phase boundary

The xBiFeO3‐(1‐x)Ba(Zr0.02Ti0.98)O3 + 1.0 mol% MnO2 (xBF‐BZT) lead‐free piezoelectric ceramics were prepared by conventional solid‐state reaction method. The structure, dielectric, and piezoelectric properties were studied. X‐ray diffraction (XRD) analysis showed that xBF‐BZT ceramics exhibited pure perovskite structure with the coexistence of tetragonal and rhombohedral phases (0.66 ≤ x ≤ 0.74). The Curie temperature Tc, the dielectric constant εr (1 kHz), dielectric loss tanδ (1 kHz), piezoelectric constant d33, coercive field Ec (80 kV/cm), and remnant polarization Pr (80 kV/cm) of 0.7BF‐0.3BZT‐Mn ceramics were 491°C, 633, 0.044, 165 pC/N, 35.6 kV/cm, and 22.6 μC/cm2, respectively. The unipolar strain of 0.7BF‐0.3BZT reached up to 0.20% under the electric field of 60 kV/cm, which is larger than that (0.15%) of BiFeO3–BaTiO3 ceramics. These results indicated that the xBF‐BZT ceramics were promising candidates for high‐temperature piezoelectric materials.