Effects of Sn on the microstructure and dielectric properties in BaTiO3-based ceramics

Ba0.985Bi0.01TiO3–BaTi1−xSnxO3 powders were synthesized by a two-step soft chemical method. Ceramics with core–shell structure could be easily obtained by using these uniformly distributed powders. The ceramics not only satisfied the requirement of EIA-X8R specification, but also were near to that of EIA-X9R specification. Microstructural evaluation conducted by X-ray diffraction and scanning electron microscopy confirmed the hierarchical structure of the ceramic grains. The shape of the ε–T curves near the dielectric peak became broad when x increased from 0.001 to 0.02. The permittivity of Ba0.985Bi0.01TiO3–BaTi0.98Sn0.02O3 ceramic was ∼23,000, ΔC/C20 °C was −15%, 14.4% and −15% at −55 °C, 120 °C and 170 °C, respectively, and the dielectric loss was 0.5. The results showed that the content of Sn had a strong impact on the diffusion and the dielectric properties of the ceramics.