The microstructure analysis of cerium-modified barium titanate having core-shell structured grains

The microstructure of chemical inhomogeneity having the core-shell structured grain of cerium-modified barium titanate was investigated using Xray, TEM, dilatometer and DSC methods. Specific heat anomalies, thermal expansion anomalies and lattice parameter discontinuities were associated with the three ferroelectric transitions (T-c, T-1 and T-2) of the grain-core of BaTiO3. The crystal symmetry of the chemically inhomogeneous grain was strongly dependent on the cerium concentration and temperature. In comparison to other physical quantities, the temperature dependence of the dielectric constant was easily influenced by stress. (C) 1997 Elsevier Science Limited and Techna S.r.l.