Dielectric and Piezoelectric Properties of (A_0.5Bi_0.5)TiO₃–ANbO₃ (A=Na, K) Systems

Abstract

The microstructural, dielectric and piezoelectric properties of the (Na 0.5 Bi 0.5 )TiO 3 –NaNbO 3 and (K 0.5 Bi 0.5 )TiO 3 –KNbO 3 systems were studied in order to find new lead-free piezoelectric ceramic materials. In the (1- X ) (K 0.5 Bi 0.5 )TiO 3 –( X ) KNbO 3 system, it was confirmed from the measurements of the electromechanical coupling factor, K p , that piezoelectricity occurred within the wide compositional range between X =0 and 0.35. The sample with X =0.075 showed a maximum K p of 15.1%. However, the expected morphotropic phase boundaries were not found in the (Na 0.5 Bi 0.5 )TiO 3 or (K 0.5 Bi 0.5 )TiO 3 rich side of the solid solution systems.