Enhanced temperature stability of modified (K0.5Na0.5)(0.94)Li0.06NbO3 lead-free piezoelectric ceramics

摘要

To improve both the temperature stability and the mechanical quality factor of (K0.5Na0.5)(0.94)Li0.06NbO3 (KNLN6) ceramics, dense (K4CuNb8O23, Bi2O3)-modified KNLN6 lead-free ceramics were prepared. Results showed that the (K4CuNb8O23, Bi2O3)-modified ceramics exhibited a flat, temperature-stable behavior over the range of 20-120 A degrees C. K4CuNb8O23 (KCN) and Bi2O3-codoping changed the KNLN6 to "hard" ceramics with a significant improvement of mechanical quality factor, Q (m), from 82 to 756. Meanwhile, the piezoelectric constant, d (33), and the planar electromechanical coefficient, k (p), still maintained relatively high levels (d (33) similar to 118 pC/N, k (p) similar to 35.6%). These results indicate that the modified KNLN6 ceramics are promising lead-free piezoelectric candidates for practical applications.