Small-signal A.C. response theory for systems exhibiting impurity oxygen transport
Abstract A theoretical expression is obtained for the small-signal a.c. response of a solid electrolyte in contact with two identical metal electrodes when impurity oxygen is present as an adsorbed species at the electrode/electrolyte interface, is mobile in both the electrode and the electrolyte, and exchanges at the interface with one of the intrinsic charge carriers in the electrolyte. The system response function (impedance or admittance) can be represented by an equivalent electrical circuit consisting of resistive and capacitative elements combined with two finite-length Warburg elements which represent oxygen transport through the electrolyte and the electrode.