Effect of external electric field on the grain growth of barium titanate in N2 atmosphere

The effect of dc electric field upon the spatial variation of microstructure during the sintering of BaTiO3 in a N2 atmosphere was investigated. When BaTiO3 specimens were heat-treated in a N2 atmosphere at 1350 ∘C under an electric field, grain growth was enhanced at the positive-biased region for a 0.5 mol% Nb-doped specimen, while it was promoted at the negative-biased region for a 3.0 mol% Nb-doped specimen. The grain growth behavior at both the positive and negative-biased region was similar for a 1.0 mol% Nb-doped specimen. The results have been explained mainly in terms of the boundary potential, which varies with the donor concentration, and the oxygen partial pressure of the surrounding atmosphere.