LEIS370
Localised Electrochemical Impedance System
The LEIS370 allows spatially resolved impedance measurements to be made, combining established principles of EIS measurements with scanning probe technology.
The principles of LEIS are similar to those employed in traditional bulk EIS, in that a small sinusoidal voltage or current perturbation is applied to a working electrode sample and the resulting current is measured to allow the calculation of the impedance. However, rather than measure the bulk current, a small electrochemical probe is scanned close to the surface, measuring the local current in the electrolyte. Applications for localised electrochemical impedance spectroscopy include -
- Degradation of organic coatings
- Kinetics of activation and passivation of metals
- Local impedance variations on surfaces of materials in resistive media
- Characterising alloys in aerospace, automotive and electronics applications
- Studying biofilms on metal surfaces
Software Control
The LEIS370 software is 32-bit, Microsoft® Windows™ based, and provides the user with complete control of the potentiostat/galvanostat and lock-in amplifier/FRA as well as the LEIS370. Full frequency sweeps of individual points of interest or a feature on the surface of a sample are easily set with a few clicks of the mouse.
Mapping of impedance data over the surface of the sample at a single frequency has never been easier. Real-time display of the data provides the user with instant feedback on the phase or magnitude of the impedance values measured. As an alternative, it is possible to measure the magnitude and phase of the voltage, current or admittance as well. In addition, the LEIS370 allows the user to make galvanic or bulk impedance measurements simply by choosing which mode the potentiostat is operating in, and the software does the rest.
The LEIS370 software provides the user with a high degree of control over the experimental parameters as well as graphical features. The area scan images are easily exported into a text document as a bitmap image, or the data can be exported into a data spreadsheet for further analysis. The optional IsoPlot™ 3-D Surface Rendering Software allows the user to control viewing, light angles, colour and plotting parameters.