Phase Transition Temperatures of Divalent and Trivalent Ions Substituted (Bi{sub}(1/2)Na{sub}(1/2))TiO{sub}3 Ceramics

摘要

The phase transition temperatures of divalent and trivalent ions substituted (Bi{sub}(1/2)Na{sub}(1/2))TiO{sub}3 ceramics were investigated in detail by electrical measurement. BNT ceramics substituted by divalent (Ca{sup}(2+), Sr{sup}(2+) and Ba{sup}(2+)) and trivalent (La{sup}(3+), Nd{sup}(3+), Ho{sup}(3+) and Yb{sup}(3+)) ions were prepared by conventional ceramic fabrication process. For these ceramics, the depolarization temperature, T{sub}d, the rhombohedral-tetragonal phase transition temperature, T{sub}(R-T), and the temperature of the maximum dielectric constant, T{sub}m, 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.