An approach to further improve piezoelectric properties of (K0.5Na0.5)NbO3-based lead-free ceramics

An approach to further improve piezoelectric properties of (1-x)(K0.5Na0.5)NbO3-xLiNbO(3) (KNLN) ceramics, i.e., the optimum poling temperatures (T-p) of KNLN ceramics should be chosen near the polymorphic phase transition temperatures, is proposed. This is contrary to conventional wisdom associated with electrical poling of ceramics. Piezoelectric constant d(33) of KNLN (x=0.07) ceramics increases from 210 to 274 pC/N by selecting optimum T-p. This result indicates that this approach is very effective in improving piezoelectric properties of KNLN ceramics. Moreover, this approach can also be applied to other (K0.5Na0.5)NbO3 based ceramics. (c) 2007 American Institute of Physics.