Effects of Bi₄Ti₃O₁₂ addition on the microstructure and dielectric properties of modified BaTiO₃ under a reducing atmosphere

The effects of Bi₄Ti₃O₁₂ addition on the microstructure and dielectric properties of Mn-modified BaTiO₃ were investigated to develop low temperature fired BaTiO₃-based ceramics with stable temperature characteristics. The sintering temperature of Mn-doped BaTiO₃ could be reduced to 1200 °C by adding more than 1 mol% Bi₄Ti₃O₁₂. TEM results show an apparent core-shell structure with 2 mol% Bi₄Ti₃O₁₂ addition. However, it was destroyed when the Bi₄Ti₃O₁₂ content increased from 2 to 4 mol%. The permittivity decreased and the Curie temperature shifted to higher temperature when the Bi₄Ti₃O₁₂ content increased from 0 to 3 mol%. The temperature characteristic of capacitance was very close to the EIA X8R specification when 2 mol% Bi₄Ti₃O₁₂ was added due to the presence of the core-shell grain structure and raised Curie temperature. With adequate Bi₄Ti₃O₁₂ addition, the BaTiO₃-based system shows great potential for applications in EIA X8R-type multilayer ceramic capacitors.