Core‐Shell Structures in ZrO ₂ ‐Modified BaTiO ₃ Ceramic

Abstract

Pure BaTiO 3 exhibits a paraelectric‐to‐ferroelectric phase transition at 130°C. When stoichiometric BaTiO 3 is combined with 10 mol% ZrO 2 , the relative permittivity (ε) changes to a broad, relatively insignificant temperature dependence, and the Curie point, T c , is not sharply defined. However, the transition sharpens at T = 95°C when these samples are sintered for a longer period of 60 h. SEM, EDAX analysis coupled with TEM observation gives three types of core‐shell structures of different microstructural characteristics which are related to the diffuse phase transition. Chemical inhomogeneity, due to Zr 4+ distribution in the core‐shell structure, is proposed to account for the diffuse phase transition behavior.