Influence of Ge and Si Doping on the Microstructure and Dielectric Properties of Barium Titanate Ceramics

Abstract

GeO2 has been doped solely and together with SiO2 into barium titanate ceramics by mixing and calcination. The microstructure and dielectric properties of doped BaTiO3 have been characterized. When doped in BaTiO3, Ge4+ ion could incorporated into the crystal lattice of BaTiO3 to occupied Ti4+ sites. For relative smaller Ge4+ ion, the tetragonal phase could be enhanced. As dielectric properties have strong relation to tetragonal phase. The relative permittivity could be increased in this mechanism. However, the high leakage current which induced by more ionic defect was also lead to high dielectric loss. Besides, the assemble in grain boundary by Ge4+ ion may also have effect. Results on the GeO2-SiO2 co-doped sample showed that the mechanisms of Ge doping and Si doing could happen at one time.