Fitting procedure based on Differential Evolution to evaluate impedance parameters of metal-coating systems

Abstract

Impedance data obtained by Electrochemical Impedance Spectroscopy (EIS) are fitted to a relevant electrical equivalent circuit in order to evaluate parameters directly related to the resistance and the durability of coated metal systems. An alternative method to non-linear regression algorithms for the analysis of measured data in terms of equivalent circuit parameters is provided by evolutionary algorithms, more especially the differential evolution (DE) algorithms (standard DE and a representative of the self-adaptive DE paradigm were used). Obtained results with DE algorithms were compared with commercial fitting software achieving a more accurate solution in all handled cases.