Microstructure and piezoelectric properties of Na0.5K0.5NbO3-BiNiO3-LiSbO3 lead-free ceramics

Lead-free (0.94-x)Na0.5K0.5NbO3-xBiNiO(3)-0.06LiSbO(3) piezoelectric ceramics have been sintered at 1105 degrees C by ordinary solid mixed oxide method. The phase transitional behavior and various electrical properties were investigated. All samples are typical ABO(3) style perovskite structure. A morphotropic phase boundary between orthorhombic and tetragonal ferroelectric phases has been identified in the composition range of 0.002 <= x <= 0.004. Main piezoelectric parameters of these ceramics were optimized around x = 0.002 with an enhanced piezoelectric constant d(33) of 240 pCN(-1), a planar electromechanical coefficient k(p) of 44%, a mechanical factor Q(m) of 38, and a Curie temperature T-c of 360 degrees C. These results indicate the materials studied have a promising future in a wide range of applications. (C) 2010 Elsevier B.V. All rights reserved.