Effects of CaAl2O4 on the electrical properties and temperature stability of (Na0.53K0.404Li0.066)Nb0.92Sb0.08O3 ceramics

Abstract Lead-free (1 −  x )(Na 0.53 K 0.404 Li 0.066 )Nb 0.92 Sb 0.08 O 3  +  x CaAl 2 O 4 (NKLNS– x CA) ceramics were prepared by the conventional mixed oxide method. The effects of the addition of CaAl 2 O 4 on the phase transitions and electrical properties of the KNN-based ceramics were studied and the temperature stability of their piezoelectric and electromechanical properties was also discussed. It is found that 1.5 mol% CaAl 2 O 4 doped NKLNS ceramic exhibits stable piezoelectric and electromechanical properties in −40 to 60 °C due to the extended polymorphic phase transition region induced by the B -site composition fluctuation. The piezoelectric constant d 33 , dielectric loss tan δ , and electromechanical coupling factor k p of the NKLNS–0.0150CA ceramic are found to be 254 pC/N, 3.5%, and 45%, respectively, demonstrating that the NKLNS–0.0150CA ceramic is a very promising lead-free piezoelectric material for practical applications.