The Effect of TiO2 on the Dielectric Performance of ZrO2 and Nb2O5 Pre-Doped CaCu3Ti4O12 Ceramics

In this work, the effects of different sintering temperatures and TiO₂ concentrations on the dielectric properties of ZrO₂ and Nb₂O₅ pre-doped CaCu₃Ti₄O₁₂ (CCTO) ceramics were investigated. These doped ceramics were sintered at temperatures of 1020, 1030, and 1040 °C, exhibiting the lowest dielectric loss of 0.01, which consistently remained below 0.03 across a wide frequency range from 10 to 10⁵ Hz. Simultaneously, they maintained a high dielectric constant of more than 3000 and remarkably met the requirements for an X8P capacitor (Δε' ≤ ±10% at temperature range from -55 to 150 °C). It was clarified that TiO₂ doping increased grain boundary resistance, leading to the reduced dielectric loss, and elevated the grain boundary activation energy, thereby enhancing the temperature stability. The TiO₂-doped CCTO-based ceramics also demonstrated reduced sensitivity to variations in sintering temperature, highlighting their excellent manufacturability. This characteristic holds great promise for the fabrication of CCTO-based ceramics, which usually exhibit poor repetitiveness.