CORE-SHELL STRUCTURES IN ZRO2-MODIFIED BATIO3 CERAMIC

Pure BaTiO3 exhibits a paraelectric-to-ferroelectric phase transition at 130-degrees-C. When stoichiometric BaTiO3 is combined with 10 mol% ZrO2, the relative permittivity (epsilon-r) 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-degrees-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 behavior.