THE NUMERICAL EVALUATION OF THE DISTORTION OF EIS DATA DUE TO THE DISTRIBUTION OF PARAMETERS

It is assumed that in a number of cases the typical 'depressed semicir cles' and other distortion phenomena are caused by a distribution of p arameter values due to surface inhomogeneities. A model is proposed to treat these distortions in terms of the distributions of the paramete rs (average, variance, covariance and higher moments). It is shown tha t the phase angle of the impedance is invariant with the distortions c aused by the surface inhomogeneities. The mathematical results and the ir consequences are discussed and demonstrated on simulation diagrams of two frequently used equivalent circuits. (C) 1997 Elsevier Science S.A