Comprehensive investigation of structural and electrical properties of (Bi, Na) CoZrO 3 -doped KNN ceramics

Abstract This study utilized the traditional solid state reaction method to fabricate 0.965(K 0.48 Na 0.52 )Nb 0.96 Sb 0.04 O 3 -0.035[(Bi 0.5 Na 0.5 ) 1-x Co x ZrO 3 ](KNNS-BNC x Z) lead-free ceramics for the sake of investigating the influences of BiCoZrO 3 -doped on the crystalline structure, microstructure, and dielectric/piezoelectric properties of the ceramics. The KNNS-BNC x Z ceramics exhibited a perovskite structure, which changed from a three-phase coexistence of rhombohedral-orthorhombic-tetragonal (R-O-T) to orthorhombic (O) with increasing x . The surface morphologies further indicated that different amounts of (BiNa)CoZrO 3 played a large effect on the grain growth. In addition, the optimal combined properties ( d 33  = 418 pC/N, k p  = 0.48, T c  = 263 °C) were simultaneously obtained at x  = 0.1. Particularly, good thermal stability was observed in a broad temperature range ( T a  = 265 °C d 33  ≥ 351 pC/N). These results induced that KNNS-BNC x Z ceramics were appropriate candidates for lead-free electronical applications.