Analysis of impedance spectroscopy data: problems and new directions

Summary form only given as follows: The author deals with the importance of analyzing impedance spectroscopy small-signal frequency-response data in ways which are appropriate to yield increased understanding of the underlying physico-chemical processes associated with the data and/or its use for process control and testing. Proper analysis requires complex nonlinear least squares fitting with appropriate weighting, and a well-developed computer program for such fitting is described. The value and power of such analysis is illustrated along with some of its problems. New analysis methods and interpretations are discussed which involve: (a) alternatives to Kronig-Kramers integral transformation; (b) new fitting models appropriate for solid materials; (c) ways of separating and understanding concomitant conduction-relaxation and dielectric-dispersion contributions to the overall response; and (d) estimation of distributions of relaxation times and barrier heights