摘要 : An equivalent circuit model is introduced to account for the impedance properties of solid state ionic conductors, composed of two distinct phases. The model is developed on the basis of physical arguments, regarding the micromete... 展开 An equivalent circuit model is introduced to account for the impedance properties of solid state ionic conductors, composed of two distinct phases. The model is developed on the basis of physical arguments, regarding the micrometer-scale structure of the two-phase material system and the comparison of different possible equivalent circuit representations. The final equivalent circuit reduces to two simpler circuits, suitable for fitting experimental impedance spectra. Computer simulations are provided to demonstrate the non-Arrhenius behaviour, which is observed in the temperature dependence of the ohmic elements of the equivalent circuits used for data analysis. This complex dual-slope behaviour of the Arrhenius plot is in agreement with the predictions of the model. Finally, with the aid of mathematical calculations and illustrated by computer simulations, a modified Arrhenius plot evaluation procedure was developed to derive correctly the electrical properties of the individual constituent phases from impedance measurements. 收起