Bi(Zn1/2Ti1/2)O3 modified BiFeO3–BaTiO3 lead-free piezoelectric ceramics with high temperature stability

Lead-free high-temperature ceramics with compositions of 0.71BiFe1−x(Zn1/2Ti1/2)xO3–0.29BaTiO3 (BFZTx–BT, x=0–0.05 mol fraction) were fabricated by a conventional solid state reaction method. The effect of Bi(Zn1/2Ti1/2)O3 (BZT) addition on the microstructure, electrical properties, relaxor behavior, and temperature stability has been studied. XRD patterns revealed that all compositions formed a single perovskite phase of pseudo-cubic crystal structure. The grain size was slightly affected by BZT addition. The diffuse phase transition and strong frequency dispersion of dielectric permittivity are observed for BZT modified ceramics. The addition of BZT into BFZTx–BT was also found to affect the piezoelectric properties and temperature stability of the ceramics with maximum values observed for x=0.5% and 1% BFZTx–BT compositions, respectively. The optimum piezoelectric properties with d33=163 pC/N, together with high-temperature stability with a depolarization temperature Td∼380 °C, reveal the BFZTx–BT ceramics to be promising high-temperature Pb-free piezoelectric materials.