Chemical composition dependence of ferroelectric properties for BaTiO3–Bi(Mg1/2Ti1/2)O3–BiFeO3 lead-free piezoelectric ceramics

The BaTiO3–Bi(Mg1/2Ti1/2)O3–BiFeO3 [(1 − x − y)BT-xBMT-yBF] ceramics were prepared by a conventional solid–state synthesis, and their crystal structure and piezoelectric properties were investigated in details. Synchrotron X-ray diffraction (XRD) pattern revealed that a single perovskite phase was obtained for samples at x = 0.050–0.150, y = 0.465–0.735. Splitting of the (111) peak was observed when (x, y) = (0.050, 0.685) and (0.050, 0.735) indicating that crystal structure of samples changed from pseudocubic to rhombohedral phase with increasing BF content. As the BF content increased, the Curie temperature increased. The highest apparent piezoelectric constant d33* values estimated from strain (S) over the applied electric-field (E) value (d33* = S/E) was observed at 300 pm/V for the 0.325BT-0.100BMT-0.575BF ceramics at 25°C and 1 Hz.