Phase relation and dielectric properties in (Bi1/2Na1/2)1-xBaxTiO3TiO3 lead-free ceramics

The diffuse phase transition behavior of the (Bi1/2Na1/2)(1-x)BaxTiO3TiO3 solid solutions were investigated from the epsilon(T) curve. The temperature due to the structural change coincided with the abrupt jump in epsilon(T) curve. The dielectric constant maximum and the dielectric constant minimum were important parameters to define the phase transition. (Bi1/2Na1/2)(1-x)BaxTiO3TiO3 system has the phase transition sequence from rohmbohedral to tetragonal. The phase transition of (Bi1/2Na1/2)(1-x)BaTiO3TiO3 system was accompanied with structural changes. When x is 0.06, 0.08 and 0.12, 0.12, (Bi1/2Na1/2)(1-x)BaxTiO3TiO3 showed the diffuse phase transition as a relaxor. (Bi1/2Na1/2)(1-x)BaxTiO3TiO3 system related to the diffuse phase transition had the antiferroelectric phase. (Bi1/2Na1/2)(0.9)Ba0.1TiO3 system showed the ferroelectric properties with the remanent polarization of 18 mu C/cm(2) and the coercive electric field of 10 kV/cm. (c) 2006 Published by Elsevier B.V.