Influence of Erbium doping on the electrical behaviour of CaCu3Ti4O12 ceramics probed by impedance spectroscopy analysis

Herein, the preparation and impedance spectroscopic investigation of pure and Er doped CaCu3Ti4O12 ceramics is reported. FTIR spectroscopy and powder XRD analysis elucidate the surface functionality and crystalline nature of the products respectively. Scanning Electron Microscopy images substantiate the homogenous formation of nanoparticles and the EDS analysis confirms the elemental composition of the products. A relatively high dielectric constant (epsilon(r) = 26,749) is found for Er doped CaCu3Ti4O12 ceramics than that of pure CaCu3Ti4O12 ceramics (epsilon(r) = 5885) at 10 Hz (at 800 K). Nyquist plot of pure and Er doped CaCu3Ti4O12 ceramics indicates the presence of a non-Debye type of relaxation phenomenon, which is further validated from the electrical modulus analysis. The variation of temperature dependent relaxation time of pure and Er doped CaCu3Ti4O12 ceramics is estimated from both the imaginary part of impedance and electrical modulus analysis.