Properties of Ba-doped Sr2Bi4Ti5O18 ceramics

Sr2-xBaxBi4Ti5O18 (SBBTi-x,x = 0 similar to 2.0) ceramic samples were prepared by using the standard solid-state reaction method and their crystal structure, ferroelectric and dielectric properties were examined. The results show that the lattice constants increase with barium content. The remnant polarization (2P(r)) and the coercive field (E-c) decrease with Ba-doping. As x = 0, they were 17.3 mu C/cm(2) and 54 kV/cm, and in the case of x = 2.00, they are 0.3 mu C/cm(2) and 1.8 kV/cm, respectively. As Ba content increases, the Curie temperature (T-c) of the SBBTi-x decreases from 285 degrees C to a minimum value of 150 degrees C at x = 0.75, then increases and reaches 300 degrees C at x = 2.00. As x < 0.75, Ba incorporation brings about the pronounced relaxor ferroelectric behavior.