Effects of Bi2O3 and Yb2O3 on the Curie Temperature in BaTiO3-Based Ceramics

Effects of doping Bi2O3 and Yb2O3 into BaTiO3‐based ceramics were investigated. The Curie temperature shifted to a higher point with an increasing BiYbO3. Yb plays a major role and Bi has no influence on the Curie point, but Bi2O3 is important because it can hinder the diffusion of other dopants and avoid the destruction of the “core–shell” structure. Moreover, the excess Bi2O3 addition enhances the effect of Yb2O3 on shifting Tc. X‐ray diffraction analysis indicated that the c/a ratio increased with the increasing of BiYbO3. The rise of the Curie temperature is attributed to an internal stress caused by the lattice mismatch between grain cores and grain shells. The dielectric properties can also be explained by the “core–shell” structure.