Dielectric, ferroelectric, and piezoelectric properties of the lead-free (1−x)(Na0.5Bi0.5)TiO3-xBiAlO3 solid solution

Lead-free piezoelectric ceramics derived from the solid solution of (1−x)(Na0.5Bi0.5)TiO3–xBiAlO3 (NBT-BA) (x=0–0.10) have been synthesized by solid state reactions. A pure perovskite phase was formed for x≤0.08. The temperature dependence of dielectric constant indicates an increased broadness of the dielectric peak as the amount of BA increases. The large dielectric loss of NBT ceramics at low frequency and high temperature has been significantly reduced by the substitution of BA. The high coercive field is decreased and ferroelectric hysteresis loops were displayed at room temperature. The NBT-BA ceramics exhibit improved ferroelectric and piezoelectric properties compared to pure NBT ceramics, with Pr=52 μC/cm2, Ec=44 kV/cm, d33=130 pC/N, and kp=0.23 for 0.92NBT–0.08BA.