Local electrochemical impedance spectroscopy LEIS

Measixrement techniques Bridge mechanical generator Bridge electronic generator Impulse method, oscillograph, Laplace transform Analogue impedance measurement, potentiostat (AC + DC) Digital impedance measurement, cormection with computer Local electrochemical impedance spectroscopy (LEIS)... 

Remember 7.4 Local Electrochemical Impedance Spectroscopy (LEIS) is a relatively new and underutilized technique that is useful for exploring the influence cf surface heterogeneities on the impedance response. 

Recently, two new electrochemical mapping techniques have become available the scanning vibrating electrode technique (SVET) and the localized electrochemical impedance spectroscopy (LEIS) technique. These techniques provide the capability to identify and monitor electrochemical behavior down to the micron level. These represent significant advances over traditional electrochemical methods (cyclic voltammetry, EIS, and even EQCM), which provide data that reflect only an average over the entire sample surface. Although such data are very useful, a major drawback is that no local or spatial information is obtained. 

Lillard and coworkers developed a method called Local Electrochemical Impedance Spectroscopy LEIS [39). It relies on the fact that ac current densities in the solution very near to the working electrode are proportional to the local impedance properties of the electrode. In order to determine the current densities normal to the surface, the ac potential drop was measured between planes parallel to the electrode surface employing a two-electrode microprobe. A schematic of a commercially available experimental setup for LEIS is... 

The local electrochemical impedance spectroscopy (LEIS) " is another scanning probe technique that can map the ac impedance distribution over an electrode surface. In LEIS a sinusoidal voltage perturbation between the working and reference electrode is maintained by driving an ac current between the working... 

LEIS Localized (scanning) electrochemical impedance spectroscopy... 

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