High Curie temperature of (Li, K, Ag)-modified (K0.50Na0.50)NbO3 lead-free piezoelectric ceramics

Abstract (1 −  x )[(K 0.50 Na 0.50 ) 0.955 Li 0.055 ]NbO 3 - x (Ag 0.5 K 0.5 )NbO 3 [(1 −  x )KNLN- x AKN] new lead-free piezoelectric ceramics were prepared by the conventional mixed oxide method. Effects of the AKN content on the Curie temperature and piezoelectric properties of (1 −  x )KNLN- x AKN ceramics were systematically investigated. The experimental results show that the Curie temperature of the ceramics was improved by doping AKN, and the ceramics with x  = 0.02 exhibit high Curie temperature and relatively good piezoelectric properties ( d 33  = 176 pC/N and T c  = 479 °C). These results show that (1 −  x )KNLN- x AKN ceramic with x  = 0.02 is a good lead-free piezoelectric ceramics for high temperature application.