Microstructures and dielectric properties of Y/Zn codoped BaTiO3 ceramics

The microstructures and dielectric properties of Y/Zn codoped BaTiO3 ceramics sintered in a reducing atmosphere were investigated. XRD analysis indicated the crystal structure of samples change from tetragonal to pseudocubic with increasing Y2O3 and ZnO content. SEM micrographs showed Y2O3 can suppress grain growth more effectively compared with ZnO, which is ascribed to the presence of second phase Y2Ti2O7. Proper amount of Y2O3 and ZnO can significantly improve the dielectric temperature characteristics due to the formation of grain core-shell structure. The high performance dielectrics meeting the X7R code were achieved by codoping 1.5 mol% Y2O3 and 3.0 mol% ZnO