Microstructure and dielectric properties of CaCu₃Ti₄O₁₂-xCeO₂ ceramics

(1-x)CaCu₃Ti₄O₁₂-xCeO₂ (x=0.1, 0.2, 0.3, 0.4) and CaCu₃Ti₄O₁₂ ceramics were synthesized through a solid-state reaction technique. X-ray diffraction indicates that the CaCu₃Ti₄O₁₂ phase is formed in all ceramics. SEM micrographs show that the grain size of ceramics declines with the addition of CeO₂, which is attributed to the solute drag effect. When the addition amount of CeO₂ is 0.4, the ceramic obtains the maximum dielectric constant at low frequency. Increasing the composite content of CeO₂ can effectively reduce the dielectric loss of CCTO ceramics at high frequency. And the lowest value is 0.1 when the addition amount of CeO₂ is 0.3. Impedance analysis shows that the lowest dielectric loss obtained for the ceramic is due to the lowest grain resistance.