Effect of TiO2 nanoparticles on dielectric properties of CuO ceramics

We reported the dielectric properties of CuO_-xTiO₂ (CT) (x=0, 0.02, 0.01, and 0.20) ceramics prepared by a conventional mixed oxide method. X-ray diffraction and scanning electron microscopy were used to characterize the phase formation and microstructure of the CT ceramics, respectively. The microstructure analysis showed that the nanoparticles of TiO₂ were accumulated in the microstructure both of grain boundaries and the outmost surface layer of the ceramics. The dielectric constant of the CT ceramics decreased with increasing the concentration of the TiO₂ content. Our result also revealed that the concentration of TiO₂ had a remarkable influence on the dielectric relaxation of the CT ceramics. The giant dielectric properties of theses CT ceramics might be ascribed based on the interfacial polarization at the grain boundary and the surface layers.