Effect of SiO2 addition on the dielectric properties and microstructure of BaTiO3-based ceramics in reducing sintering

The effect of SiO2 doping on the sintering behavior,microstructure,and dielectric properties of BaTiO3-based ceramics has been investigated.Silica was added to the BaTiO3-based powder prepared by the solid state method with 0.075mo1%,0.15mo1%,and 0.3mo1%,respectively.The SiO2-doped BaTiO3-based ceramic with high density and uniform grain size were obtained,which were sintered in reducing atmosphere.A scanning electron microscope,X-ray diffraction,and LCR meter were used to determine the microstructure as well as the dielectric properties.SiO2 can form a liquid phase belonging to the ternary system of BaO-TiO2-SiO2,leading to the formation of BaTiO3 ceramics with high density at a lower sintering temperature.The SiO2-doped BaTiO3-based ce-ramics can be sintered to a theoretical density higher than 95% at 1220℃ with a soaking time of 2 h.The dielectric constants of the sample with 0.15mo1% SiO2 addition sintered at 1220℃ is about 9000.Doping with a small amount of silica can improve the sinter-ing and dielectric properties of BaTiO3-based ceramics.