Structural and impedance spectroscopic studies of spark plasma sintered CaCu3Ti4O12 dielectric ceramics: an evidence of internal resistive barrier effect

摘要: A giant dielectric constant CaCu3Ti4O12 ceramic was prepared by solid-state reaction route. Powders were spark plasma sintered at 1050 °C for 30 min. Rietveld refined XRD pattern reveals the formation of pure phase cubic perovskite CCTO. The properties characterized in a broad frequency range 10 Hz–8 MHz temperatures 20–120 °C. grain size pellets found 12–15 μm. Impedance spectroscopic analysis shows that observed semicircle Cole–Cole plot associated with boundary relaxation effect. This study there is an evidence internal resistive barrier which responsible ceramic. An Arrhenius temperature dependent effect boundary. Using characteristic peak, capacitance calculated to be 0.27 μF. It on increasing temperature, resistance boundaries decreased rapidly as compared grains. activation energy 0.165 eV.