Grain boundary effects on piezoelectric properties of the core–shell-structured BaTiO3@TiO2 ceramics

Grain boundary effect on BaTiO 3 has been widely investigated for several decades. However, all of them tailored the grain boundary by grain size of BaTiO 3 . In this case, a direct way was introduced to modify the grain boundary by coating technique to investigate the role of grain boundary in ferroelectric materials. Nonferroelectric phase TiO 2 was employed to investigate grain boundary effects on the electrical properties of BaTiO 3 piezoelectric ceramics. TiO 2 coating can result in the reduction of piezoelectric and ferroelectric properties and the annealing process in oxygen can increase piezoelectric behavior of pure BaTiO 3 due to valence state of Ti ions while that remains for Ti-modified composition possibly due to the increased grain boundary effect by impedance analysis. Compared with ferroelectric grain, grain boundary plays a critical role to impact the electrical properties of perovskite-type ferroelectric materials.