저널

The temperature and frequency dependence of the dielectric constant of the BaTiO3 substituted with two types of donor dopants, Nb5+ and Ta5+, respectively, were compared and analyzed. Dielectric specimens of four specific compositions, Ba0.95Nb0.05TiO3, Ba0.90Nb0.10TiO3, Ba0.95Ta0.05TiO3, and Ba0.90Ta0.10TiO3 were prepared by calcining at 1100 °C and sintering at 1300 °C to have a perovskite structure to measure capacitance. XRD and SEM analysis were used to observe the structure, with particular focus on the integration into the Nb5+ and Ta5+ substituted BaTiO3 crystal lattice. X-ray diffraction peaks in the (200) and (002) planes were observed between 45.10o and 45.45o of the BaTiO3 solid solution substituted with different fractions of Nb5+ and Ta5+. The dielectric properties were analyzed and the relationship between the properties and structure of the substituted BaTiO3 was established. The fine particles and high density of the substituted BaTiO3 were maintained like pure BaTiO3, and in particular, a shift toward the low temperature side of the phase transition temperature range was clearly found, unlike pure BaTiO3. In addition, the phase transition at a temperature higher than the Curie temperature relatively satisfies the modified Curie-Weiss law.

BaTiO3, Dielectric properties, Modified Curie-Weiss law