Dielectric properties and study of AC electrical conduction mechanisms by non-overlapping small polaron tunneling model in Bis(4-acetylanilinium) tetrachlorocuprate(II) compound

In the present work, the synthesis and characterization of the Bis(4-acetylanilinium) tetrachlorocuprate(II) compound are presented. The structure of this compound is analyzed by X-ray diffraction which confirms the formation of single phase and is in good agreement the literature. Indeed, the Thermo gravimetric Analysis (TGA) shows that the decomposition of the compound is observed in the range of 420-520 K. However, the differential thermal analysis (DTA) indicates the presence of a phase transition at T=363 k. Furthermore, the dielectric properties and AC conductivity were studied over a temperature range (338-413 K) and frequency range (200 Hz-5 MHz) using complex impedance spectroscopy. Dielectric measurements confirmed such thermal analyses by exhibiting the presence of an anomaly in the temperature range of 358-373 K. The complex impedance plots are analyzed by an electrical equivalent circuit consisting of resistance, constant phase element (CPE) and capacitance. The activation energy values of two distinct regions are obtained from log sigma T vs 1000/T plot and are found to be E=1.27 eV (T < 363 K) and E=1.09 eV (363 K < T).The frequency dependence of ac conductivity, sigma(ac), has been analyzed by Jonscher's universal power law sigma(omega)=sigma(dc) +A omega(s). The value of s is to be temperature-dependent, which has a tendency to increase with temperature and the non-overlapping small polaron tunneling (NSPT) model is the most applicable conduction mechanism in the title compound. (C) 2016 Published by Elsevier B.V.