Changes in dielectric properties of Sb2O3 doped BaTiO3 solid solution

Abstract

Ferroelectric materials can be modified into materials with physical properties suitable for specific appli-cations 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 an-timony 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 treat-ment at 1290–1350°C for 2–5 hours. In addition, the partial penetration of Sb3+ into BaTiO3 of the com-plex 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, indi-cating a tailoring effect. In addition, it was observed that the phase transition temperature slightly changed from 68oC to 61oC 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 ferroelec-trics. 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)].