〈 001 〉 textured (K0.5 Na0.5) (Nb 0.97 Sb0.03) O3 piezoelectric ceramics with high electromechanical coupling over a broad temperature range

Abstract

〈 001 〉 -oriented (K0.5 Na0.5) (Nb 0.97Sb0.03) O3 (KNNS) ceramics with a narrow orientation distribution (full width at half maximum=7.0°) were produced by templated grain growth using NaNbO3 templates. Excellent electromechanical properties were obtained from -70 °C to the polymorphic phase transition (PPT) at 160 °C. Textured KNNS ceramics show very high electromechanical coupling factors kp =0.64 and k31 =0.37, high piezoelectric constants d33 =208-218 pC/N and d31 =-82 pC/N, and modest strain hysteresis (6.3%) at room temperature. These properties are superior to those of randomly oriented KNN-based ceramics with similar PPT temperatures. © 2009 American Institute of Physics.