Enhanced Temperature Stability of (1 − x)(K0.5Na0.5)0.94Li0.06NbO3-x(Bi0.5Na0.5)TiO3 Lead-Free Piezoelectric Ceramics

(1 − x )(K 0.5 Na 0.5 ) 0.94 Li 0.06 NbO 3 - x (Bi 0.5 Na 0.5 )TiO 3 (KNLN6- x BNT) lead-free piezoelectric ceramics with dense microstructures and good temperature stability were prepared by conventional sintering. The effects of the BNT on the structure, electrical properties, and temperature stability of the ceramics were studied. The results showed that BNT doping shifted the polymorphic phase transition below room temperature and significantly improved the temperature stability of KNLN6 ceramics. It was found that the KNLN6 ceramics doped with 3 mol.% BNT exhibited good temperature stability in the temperature range of 25°C to 180°C, as well as good electrical properties ( d 33 = 152 pC/N, k p = 37.1%, Q m = 108, ε r = 634, tan δ = 0.018 and T c = 415°C), suggesting that this material should be an attractive lead-free material for piezoelectric applications.