Effect of (Li,Ce) doping in Aurivillius phase material Na0.25K0.25Bi2.5Nb2O9

The effect of (Li,Ce) substitution for A site on the properties of Na0.25K0.25Bi2.5Nb2O9-based ceramics was investigated. The piezoelectric activity of Na0.25K0.25Bi2.5Nb2O9-based ceramics is significantly improved by the modification of lithium and cerium. The Curie temperature (T-C) gradually increases from 668 to 684 degrees C with increasing the (Li,Ce) modification. The piezoelectric coefficient d(33) of the [(Na0.5K0.5)Bi](0.44)(LiCe)(0.03)[ ](0.03)Bi2Nb2O9 ceramic was found to be 28 pC/N, the highest value among the Na0.25K0.25Bi2.5Nb2O9-based ceramics and also almost 50% higher than the reported d(33) values of other bismuth layer-structured ferroelectric systems (similar to 5-19 pC/N). The planar coupling factors k(p) and k(t) were found to be 8.0% and 23.0%, together with the high T-C (similar to 670 degrees C) and stable piezoelectric properties, demonstrating that the (Li,Ce) modified Na0.25K0.25Bi2.5Nb2O9-based material a promising candidate for high temperature applications.