The Korean Society of Surface Science and Engineering

Ferroelectric materials can be modified into materials with physical properties suitable for specific applications by utilizing small amounts of various additives. The aim is to examine the extension of basic physical properties by oxide addition. In this study, I intend to analyze the effect of small amount of antimony oxide (Sb₂O₃) doping on the structural and dielectric properties of barium titanate (BaTiO₃). A BaTiO₃ sample doped with 0.5 mol% Sb₂O₃ was synthesized. It was confirmed that the size of BaTiO₃ grains can be changed by doping a small amount of Sb₂O₃ into pure BaTiO₃ and performing heat treatment at 1290–1350℃ for 2–5 hours. In addition, the partial penetration of Sb³⁺ into BaTiO₃ of the complex crystal structure was able to exert a remarkable effect on the change in dielectric properties. The dielectric constant of BaTiO₃ doped with Sb₂O₃ was measured in the range of 0.1 kHz to 1.0 MHz after polarization with an electric field of DC 25 kV/cm, and the result was approximately 4770–5260, indicating a tailoring effect. In addition, it was observed that the phase transition temperature slightly changed from 68℃ to 61℃ toward a lower temperature. Compared with BaTiO₃, when Sb₂O₃ partially penetrated into the perovskite Ti⁴⁺ sites, the temperature-dependent dielectric constant curve showed a relatively delayed slope and also exhibited characteristics similar to those of pseudo-diffusion ferroelectrics. In addition, in the case of Sb₂O₃ doping, the phase transition phenomenon in the high-temperature range was found to relatively well satisfy a slightly modified pseudo-Curie-Weiss law according to the characteristic analysis of ln(T-Tm) vs ln[(1/K)-(1/Km)].

Keywords BaTiO₃; Sb₂O₃; Dielectrics; Oxygen vacancy.