Phase Transition Temperatures of Divalent and Trivalent Ions Substituted (Bi_1/2Na_1/2)TiO₃ Ceramics

Abstract:

The phase transition temperatures of divalent and trivalent ions substituted (Bi1/2Na1/2)TiO3 ceramics were investigated in detail by electrical measurement. BNT ceramics substituted by divalent (Ca2+, Sr2+ and Ba2+) and trivalent (La3+, Nd3+, Ho3+ and Yb3+) ions were prepared by conventional ceramic fabrication process. For these ceramics, the depolarization temperature, Td, the rhombohedral-tetragonal phase transition temperature, TR-T, and the temperature of the maximum dielectric constant, Tm, were determined on the basis of the temperature dependences of dielectric and piezoelectric properties. In this study, we demonstrated the relationship between phase transition temperature and ionic radius of ions substituted in the A-site of BNT ceramics.