Phase relation and dielectric properties in (Bi1/2 Na1/2)1−x Bax TiO3 TiO3 lead-free ceramics

The diffuse phase transition behavior of the (Bi1/2 Na1/2)1−x Bax TiO3 TiO3 solid solutions were investigated from the ε(T)ε(T) curve. The temperature due to the structural change coincided with the abrupt jump in ε(T)ε(T) curve. The dielectric constant maximum and the dielectric constant minimum were important parameters to define the phase transition. (Bi1/2 Na1/2)1−x Bax TiO3 TiO3 system has the phase transition sequence from rohmbohedral to tetragonal. The phase transition of (Bi1/2 Na1/2)1−x Bax TiO3 TiO3 system was accompanied with structural changes. When x is 0.06, 0.08 and 0.12, (Bi1/2 Na1/2)1−x Bax TiO3 TiO3 showed the diffuse phase transition as a relaxor.(Bi1/2 Na1/2)1−x Bax TiO3 TiO3 system related to the diffuse phase transition had the antiferroelectric phase. (Bi1/2 Na1/2)0.9 Ba0.1 TiO3 system showed the ferroelectric properties with the remanent polarization of 18 μ C/cm2 and the coercive electric field of 10 kV/cm.