Ferroelectric Properties of Bi3.25Gd0.75Ti2.97V0.03O12
Bi3.25Gd0.75Ti2.97V0.03O12(BGTV)ceramic were prepared by solid state reaction. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed plate-like grains with random orientation. BGTV caused a large shift of the Curie temperature ( TC) of Bi4Ti3O12(BIT) from 675°C to 398°C. The remanent polarization and the coercive field of the BGTV were 30μC/cm2and 52kV/cm at an electric field of 87kV/cm, respectively. Furthermore, the dielectric permittivity and dissipation factor were 300 and 0.003 at 1MHz, at 1V and at room temperature, respectively. These ferroelectric properties of BGTV are superior to V-doped Bi4Ti3O12(~20μC/cm2and 80kV/cm) and (Sr, Ta)-doped Bi4Ti3O12(~12μC/cm2and 71kV/cm) ceramics. In addition, the dense ceramics of BGTV could be obtained by sintering at temperatures 100─200°C lower than those of the SrBi2Ta2O9system.