Enhancing piezoelectric properties by introducing Ni ion into B–site of Li/Sb-modified (K,Na)NbO₃ Pb-free piezoceramics

Abstract

By introducing Ni ion into the B–site of perovskite lattice, (K_0.47Na_0.51Li_0.02)(Nb_0.94−xSb_0.06Ni_x)O₃ (KNN-LSN, x = 0, 0.002, 0.005, and 0.008) Pb-free piezoceramics were prepared by solid state reaction method. The effect of Ni doping amounts on the structure and electrical properties of KNN-LSN ceramics were investigated. XRD results showed that all ceramics had pure orthorhombic perovskite structure. The introduction of Ni ion into B–site of KNN-LSN ceramics effectively improved the electrical properties. The optimal electrical properties of d₃₃ = 192 pC/N, k_p = 38.6%, Q_m = 128, ε_r = 756, tan δ = 0.025, P_r = 25.6 µC/cm², and E_c = 1.21 kV/mm were obtained when Ni doping amount x = 0.005, indicating that this ceramic was a promising Pb-free candidate for practical use.