Changes in Dielectric Properties of Sb, Nb, and Ta-doped BaTiO3 Systems

Acceptor and donor dopants have a significant effect on the dielectric properties of BaTiO3. In this paper, Sb, Nb, and Ta were added to BaTiO3 solid solutions to analyze the specific change of dielectric property based on temperature. First, the crystal stabilization process was analyzed by X-ray difraction and scanning eletron microscopy. Second, the optimum sintering conditions were confirmed according to the results, and specimens were prepared to compare their characteristics. In this experiment, it was found that the calcining condition was similar to 1100 degrees C and the sintering condition was similar to 1300 degrees C, although the heat treatment conditions were slightly different depending on the additive materials. The dielectric constants of BaTiO3 doped with 1.0 mole% of Sb, Nb, and Ta reached 4741, 2055, and 2963 at room temperature, and the transition temperatures were similar to 67, similar to 116, and similar to 109 degrees C, respectively, which shifted to very low temperatures from the transition temperature of pure BaTiO3 (similar to 125 degrees C). The results of 1/K vs. T and ln[(1/K)-(1/K-m)] vs. ln(T-T-m) were partially different from those of pure BaTiO3, having a temperature slightly higher than the phase transition temperature. This abnormal ferroelectric phase transition property of impurity-substituted BaTiO3 was confirmed by using the modified Curie-Weiss rule.