Influence of BiFeO_3 doping on structural and electrical properties of KNN-LS based lead-free piezoceramics

摘要

(0.94 - x)K0.48Na0.52NbO3-0.06LiSbO(3)-xBiFeO(3) (KNN-LS-xBF, x = 0, 0.1, 0.3, 0.5 and 0.7%) lead- free piezoelectric ceramics were prepared by a traditional two-step solid-state reaction method. The effect of BiFeO3 (BF) content on the phase structure, microstructure, electrical properties and dielectric relaxation of KNN-LS ceramics was investigated. The XRD patterns show that all ceramics have a pure perovskite structure. BiFeO3 doping can promote the grain growth and improve electrical properties. When x = 0.3% in KNN-LS-BF, it exhibits optimum electrical performance: d(33) = 285 pC/N, k(p) = 54.3%, epsilon(r) = 2185, tan delta = 1.92%, Q(m) = 66, T-c = 340 A degrees C, gamma = 1.4732, E-c = 17.76 kV/cm, P-r = 21.48 A mu C/cm(2). It is indicated that the ceramics have the potentialities to be used as the high temperature low frequency filters.