Regensburg 2010 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 3: Poster I: Nano- and microstructured dielectrics, surfaces and interfaces, dielectric composites
DF 3.8: Poster
Montag, 22. März 2010, 15:00–17:30, Poster D1
A theoretical description of constant phase element — •Mohammad Reza Shoar Abouzari1, Frank Berkemeier2, and Guido Schmitz2 — 1Department of Physics, Zabol University, Zabol, Iran — 2Institut fuer Materialphysik, Wilhelm-Klemmstr. 10, 48149 Muenster
In most cases, the experimental results of impedance spectroscopy fit precisely to the parallel circuit of an Ohmic Resistance and a phenomenological Constant Phase Element (CPE) instead of a simple RC equivalent circuit. For this reason, this empirical model is widely used, but the physical meaning of the CPE is rarely discussed. We have introduced a physical interpretation of the CPE based on the Concept of Mismatch and Relaxation theory (CMR) of Funke et al. Complex impedance spectra of ion-conducting lithium borate network glasses are used to study the deformed shape of impedance semicircles which are usually described by a parallel circuit of R-CPE. Based on the CMR, we have introduced an equivalent circuit, named CMR-C model. It takes into account the contribution of the static glass network by introducing an additional capacitor. This model describes the experimental data accurately. Upon this model we found that the CPE can be considered to be equivalent to three basic elements, R(ω), C(ω), and C(inf) , which are defined by the parameters of the CMR.