Compositional dependence of dielectric and ferroelectric properties in BiFeO3-BaTiO3 solid solutions

Abstract

Polycrystalline (1-x)BiFeO3-xBaTiO(3) (0.11 <= x <= 0.5) ceramics have been prepared by the solid-state reaction method to investigate their phase structure, dielectric, ferroelectric, and field-induced strain behaviors. The phase was found to change from rhombohedral in BiFeO3-rich compositions to pseudocubic at a BaTiO3 content of x=0.33. The room-temperature dielectric permittivity increased with increasing BaTiO3 content regardless of phase structure, except for a small dielectric permittivity peak additionally observed at x=0.33. The (1-x)BiFeO3-xBaTiO(3) solid solutions displayed a maximum in permittivity at temperatures (T-m) above 300 degrees C in the compositional range of 0.2 <= x <= 0.5. The frequency dependence of high-temperature dielectric properties suggests that BiFeO3-BaTiO3 is a relaxor ferroelectric. Normal ferroelectric loops and large electric field-induced strains were observed for the BiFeO3-BaTiO3 ceramics. The BiFeO3-BaTiO3 shows a promising candidate for high temperature ferroelectric applications.