Piezoelectric and Ferroelectric Properties of (Bi0.5Na0.5)0.9Ba0.07Sr0.03TiO3 Lead-Free Ceramics with MnO2 Doping

Abstract

The effect of a small amount MnO₂ doping on the piezoelectric and ferroelectric properties of (Bi_0.5Na_0.5)_0.9Ba_0.07Sr_0.03TiO₃ (BNBST) lead-free ceramics prepared by the conventional mixed oxide method was systematically investigated. At x = 0.25, the MnO₂-modified BNBST ceramics exhibit optimal piezoelectric and dielectric properties (d₃₃ = 157pC/N, k_p = 33 %, Q_m = 364, tan d = 2 %, e_r = 843) and excellent ferroelectric properties composed by a higher remanent polarization P_r (P_r = 25.9 μC/cm²) and lower coercive field E_C (E_C = 2.54 kV/mm) at room temperature. Moreover, the two characteristic dielectric peaks can be observed in this ceramics.