Full characterization for material constants of a promising KNN-based lead-free piezoelectric ceramic

Potassium-sodium niobate (K1-xNaxNbO3, referred to as KNN) solid solutions, which are an important type of lead-free piezoelectric materials possessing environmentally friendly features, good piezoelectric response and high Curie temperature, have attracted considerable attention in replacing lead-based ceramics. In order to promote the application of KNN-based ceramics in piezoelectric devices, we characterized a complete set of material constants of a high performance KNN-based ceramic, that is 0.965(K0.48Na0.52) (Nb0.96Sb0.04)O-3-0.035Bi(0.)(5)Na(0.5)Zr(0.15)Hf(0.)(75)O(3) (KNNS-BNZH), whose Curie temperature is 235 'C, piezoelectric coefficient d(33) is 380 pC/N and electromechanical coupling factor k(33) is 70%. These results will benefit the design of piezoelectric transducers and actuators using lead-free piezoelectric ceramics.