Relaxor behavior of $PbxBi4Ti3+xO12+3x$ $(x=2,3)$ Aurivillius ceramics

The relaxor response of the $PbxBi4Ti3+xO12+3x$ $(x=2,3)$ Aurivillius ceramics is reported. The relaxor behavior appears with an increase of the symmetry in the ab plane of the structure and a decrease of the transition temperature. By the application of a bias field on nonpoled samples, it is possible to induce the piezoelectric response. The piezoelectric coefficient in the planar mode of −72 pC/N was measured at 210 °C for $Pb2Bi4Ti5O18$ ceramic disks. These results represent a step in the search of high-temperature piezoelectric ceramics.