Dielectric modulus response of CaCu₃Ti₄O₁₂ ceramic

The DC conductivity of the CaCu₃Ti₄O₁₂ ceramic is considerable at low frequency. The dielectric properties of the CaCu₃Ti₄O₁₂ ceramics are analyzed by dielectric spectrum, and the two relaxation processes are characterized by the dielectric modulus. The two relaxation processes are considered which are dominated by the electronic relaxation of deep bulk traps at the depletion layer edge. The low-frequency and high-frequency relaxation processes are attributed to oxygen-vacancy-related defect and native defect, respectively. It is proved that the modulus response of the CaCu₃Ti₄O₁₂ ceramic is equivalent to conductivity response at high temperature (low frequency), and the peak value of the M″ is inversely proportional to capacitance. The activation energies calculated by conductivity and modulus are equivalent to each other. The modulus spectrum is more effective to the material which has high DC conductivity at low frequency such as CCTO ceramic.