Effects of sintering temperature on microstructure and dielectric properties of Sr0.985Ce0.01TiO3 ceramics

The effects of sintering temperature on microstructure and dielectric properties of Ce doped SrTiO 3 were investigated. The dielectric properties are strongly depend on sintering temperature, the sample sintered at 1520 °C exhibits a colossal permittivity about 7000 at 1 kHz while relative permittivity of the sample sintered at 1380 °C is 770. Further investigations demonstrate that all the samples belong to P m 3 ¯ m space group and without secondary phase. The lattice parameter decrease with the increase of sintering temperature while the mean grain size of SCT (Sr 0.985 Ce 0.01 TiO 3 ) ceramics are increased. Higher sintering temperature helps to improve the dielectric properties which can be attribute to defect clusters (e.g. oxygen vacancies , Ti 3+ /Ti 4+ etc.), however the defects are more likely to become carriers in high electric field which can increase the conductivity and leakage current. With the increase of sintering temperature, the conductivity activation energies , breakdown strength and energy storage density of the samples are decreased.