Enhancement of ferroelectric properties of Na_(1/2)Bi_(1/2)TiO_3-BaTiO_3 single crystals by Ce dopings

摘要

Ferroelectric single crystal of Na_(1/2)Bi_(1/2)TiO_3-BaTiO_3 (NBT-BT) and Ce doped NBT-BT have been grown by flux technique. It is found that the addition of Ce plays a significant role in improving the ferroelectric properties of NBT-BT crystals, (ⅰ) by improving the value of the dielectric constant at room temperature and at T_m (the phase transition temperature between antiferroelectric and paraelectric phases with dielectric maximum), (ⅱ) by increasing the depolarization temperature (T_d) and T_m, (ⅲ) by increasing the degree of diffuseness, and (ⅳ) by increasing the remnant polarization (P_r) and coercive field (E_c). The reasons behind these enhancements of ferroelectric properties are discussed in detail.