Experimental Issues Associated with Measurement of Local Electrochemical Impedance

Abstract

A detailed analysis from both numerical calculations and experimental results is presented for the local electrochemical impedance spectroscopy ͑LEIS͒ measurements of a disk electrode, which accounted for the placement of the LEIS probe above the electrode surface. The calculations for an electrode with a local constant phase element behavior were in excellent agreement with experimental observations for a stainless steel electrode in a Na 2 SO 4 /NaCl ͑pH 4͒ electrolyte. Measurement of the local impedance at two positions above the electrode surface allowed estimations of the local interfacial impedance and the local ohmic impedance, which were in excellent agreement with the simulations. The results demonstrate that the local impedance measurement itself cannot be used to estimate the surface area sampled by the LEIS probe. The area sampled must be determined instead by the probe geometry.

Galvanic corrosion between zinc and carbon steel investigated by local electrochemical impedance spectroscopy

“…[22,25,[28][29][30]. This technique is based on the pioneering work of Isaac's group [25,28] and takes into account the recent developments to improve the measurements and interpretation of experimental results [22,29,30].…”

Influence of hydrogen-oxidizing bacteria on the corrosion of low carbon steel: Local electrochemical investigations

“…Both set of diagrams are very similar. In the high frequency domain, the inductive behavior is due to the cell geometry, as already described by Frateur et al [37,46]. This inductive component hides the first capacitive loop, and only the second loop corresponding to the charge transfer can be used for the fitting.…”

“…Similarly to the SECM, LEIS consisted in using a micro probe for measuring the local current density [21,[37][38][39]. The two devices require some similar apparatus, in particular for positioning the probe in the vicinity of the substrate.…”

Effect of conductivity and frequency on detection of heterogeneities in solid/liquid interfaces using local electrochemical impedance

“…It must bear in mind that in LEIM bibliography there are simpler models, that do not consider the frequency in the mathematical calculations [10], or more sophisticated that take into account even CPE elements [22,23]. Nevertheless, the simplification presented here explains why some irregularities can be localized in wider frequency range than others.…”

“…On with this technique finding that multiples factors, as smooth changes in the distance from the tip to the working electrode, affect the measurements [22,23].…”