Dielectric Properties of Ni-Doped (Ba, Sr)TiO3 Ceramics at Very Low Frequencies

Dielectric properties of (Ba, Sr)TiO3 ceramics doped with up to 2.0at% nickel were measured at frequencies from 10-3 to 10Hz. The results indicate that the ceramics have extremely high dielectric constants as large as 10000. The relaxation time obtained from the dielectric loss maximum varied by the Arrhenius law with an activation energy of 1.2eV. The TSC (Thermally Stimulated Current) study strongly suggests that the dielectric relaxation phenomena are mainly due to dielectric rotation of impurity-vacancy dipoles at gain surfaces.