Thermal-electrical like response in doped sodium bismuth titanate-based ferroelectric ceramics

Abstract

The flexoelectric effect, a type of electromechanical property, is proposed to generate thermal-electrical like response in ferroelectric ceramics; however, presently, the electric current output achieved is small. Here, we show that changing the composition of the Na0.5Bi0.5TiO3-based ceramics to improve their conductivity can enhance their thermal-electrical like response to several orders of magnitude larger than that reported earlier. We also found that the measured thermal-electrical like response mainly originates from the spontaneously polarised surface existing in ferroelectrics, which generates a flexoelectric-like response under inhomogeneous deformation. The coupling of the flexoelectric-like response and high conductivity leads to a large thermal-electrical like response.