Interfacial effect inducing thermal stability and dielectric response in CdCu3Ti4O12 ceramics

The thermal stability of dielectric materials with giant permittivity has always been a difficult/hot issue based on increasing demand for microelectronics and energy storage applications. In this work, we successfully synthesized Mg-doped CdCTO ceramics with a large permittivity via an ordinary mixed-oxide technique. Notably, the dielectric permittivity of the samples significantly increase at a low frequency of ~40–105 Hz, and especially εr > 5.0 × 104, tan δ ~ 0.1 when x = 0.10 at 1 kHz. Interestingly, the thermal stability of CdMgxCu3-xTi4O12 ceramics is closely linked with the enhanced interfacial effect. The acceptable dielectric performance was ascribed to the enhanced internal barrier layer capacitor (IBLC) effect due to the increased grain size upon Mg doping. Our findings in this work could provide useful insights as to how to simultaneously realize high thermal stability and decent dielectric performance in CdCTO and other related dielectric ceramics. [Display omitted] •Mg doped CdCu3Ti4O12 ceramics with giant permittivity and low dielectric loss were prepared via ordinary mixed-oxide technique.•Dielectric permittivity was enhanced to >5.0 × 104 at 1 kHz.•The thermal stability of CdMgxCu3-xTi4O12 ceramics is closely linked with the enhanced interfacial effect.