(K0.5Na0.5)NbO3-Bi(Mg0.5Ti0.5)O3 solid solution: phase evolution, microstructure and electrical properties

Lead-free piezoelectric ceramics with the composition of (1 - x)(K0.5Na0.5)NbO3-xBi(Mg0.5Ti0.5)O-3 [(1 - x)KNN-xBMT, 0 a parts per thousand currency sign x a parts per thousand currency sign 0.04] were synthesized via solid-state reaction method. X-ray diffraction patterns revealed that the orthorhombic-tetragonal phase transition was present for (1 - x)KNN-xBMT with increasing the content of BMT. The study of dielectric properties illustrated that both peaks of orthorhombic-tetragonal (T (O-T) ) and tetragonal-cubic (T (T-C) ) phase transitions shifted to lower temperature. Through adding BMT, the electrical properties of KNN ceramics were obviously improved. The optimized piezoelectric and ferroelectric properties with d (33) = 127 pC/N, k (p) = 36.58 %, P (r) = 22.1 mu C/cm(2) were obtained as x = 0.01.