Summary and Simple Characterization Example

In the IS field, workers ordinarily spend much time and effort in preparing materials and measuring them under closely controlled conditions. But frequeutly their 

Even in the rare cases where the data are presented adequately, one often finds either no discussion of an appropriate model or equivalent circuit or just the statement that the data fit a given equivalent circuit without either a comparison of the original data and the circuit predictions or a listing of estimates of the values of the parameters in the equivalent circuit. In most cases where such a listing is included, the estimates have been obtained by approximate methods and the reader is given no measure of their accuracy and applicability. Finally, even when an equivalent circuit is presented and used, one rarely finds any discussion of why it is the most appropriate circuit to use or any comparison with other possible fitting circuits. 

Assume that either e, the bulk dielectric constant, is known or that C has been determined from CNLS fitting of the data. In either case, b can be obtained and used in Eq. (10) to obtain from the Cr estimated value an estimate of c% the bulk concentration of the mobile positive charge carriers. Then this value of Cp may be used in Eq. (9) along with the estimated value of R to obtain an estimate of /ip, the mobility of the positive charges. Finally, the Cp estimate may be used in Eq. (11) in conjunction with the Rr estimate to calculate k% the effective reaction rate for the reacting positive charges. Thus from the four macroscopic estimates C , Cr, and Rr, one obtains estimates of the four microscopic quantities e, c% /ip, and These values and their dependences on controllable variables such as ambient temperature should then finally lead to valuable insight into the electrical behavior of the mate-rial-electrode system. 

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