Electric field induced polarization and strain of (Bi1/2Na1/2)TiO3–BaTiO3 ceramics

Abstract

This study investigated the whole composition range of the electric field induced polarization and strain of (1−x)(Bi0.5Na0.5)TiO3–xBaTiO3 ceramics fabricated by a conventional solid-state reaction. In most of the composition regions (x<0.7) except for the MPB region (0.06≤x<0.08), saturated square-shape P–E loops and large negative strains in the S–E curves, along with a high coercive field and a large remnant polarization, were obtained. In these composition ranges, the remnant polarization and maximum positive strain decreased gradually with an increasing BaTiO3 content and the coercive field reached the maximum at x=0.4. The high coercive field was intrinsically affected by (Bi0.5Na0.5)TiO3, possessing a doubling of the unit cell owing to octahedron tilting and compositional ordering. At 0.7≤x, the crystal structure became a simple tetragonal structure, and the remnant polarization and the coercive field significantly decreased with an increasing BaTiO3 content.