Effects of BiAlO3 on structure and electrical properties of K0.5Na0.5NbO3-LiSbO3 lead-free piezoceramics

(1-x)(0.948 K0.5Na0.5NbO3-0.052LiSbO(3))-xBiAlO(3) (KNNLS-xBA) lead-free piezoceramics were synthesized by conventional solid state reaction method. The compositional dependence of phase structure and electrical properties of the ceramics was systemically studied. XRD patterns revealed that all the ceramic samples possessed pure perovskite structure. In addition, polymorphic phase transition (PPT) for the ceramics with BA doping could not be observed in the measuring range from room temperature to 500 degrees C. Within the studied range of BA addition, the ceramics with x = 0.002 represented a relatively desirable balance between the degradation of the piezoelectric properties, improvement in temperature stability and mechanical quality factor. It was found that the KNNLS-0.002BA ceramics exhibited optimum overall properties (d(33) = 233 pC/N, k(p) = 35%, tan delta = 0.047, P-r = 27.3 mu C/cm(2), Qin = 56 and T-c = 349 degrees C), suggesting that this material should be a promising lead-free piezoelectric candidate for piezoelectric applications. (C) 2011 Elsevier B.V. All rights reserved.