Electrical Materials Characterization
Functional material properties are usually measured by means of electrical methods.
An important tool for materials characterization is the electrical impedance spectroscopy. Here, the AC impedance at different excitation frequencies is evaluated (for example from 20 MHz to a few ìHz ). The representation of these values gives information on conduction mechanisms, on dielectric materials properties, or on electrode interface processes.
Various devices are available for that purpose: 2 x Novocontrol Alpha Analyzer ZG4 interface , 2 x HP4284A LCR meter, 1 x Zahner Zennium)
In the area of exhaust aftertreatment technology, we use high-frequencies (up to 20 GHz) to observe the status of exhaust gas aftertreatment components. The metallic catalyst canning (housing) is used as a cavity resonator. Again, we have the appropriate equipment (Anritsu VNA Master MS2028B and MS2025B).
Furthermore, we have different devices for standard measurements (many Keithley 2700 digital multimeters, Keithley 2400 SourceMeters, Keithley electrometer 617, ...).
In several special laboratory setups, we determine other materials parameters such as the Seebeck coefficient of the material (for energy conversion or sensing purposes), impedance measurements on pressed pellets or thick layers, four-wire impedance spectroscopy on pellets or planar coatings under various atmospheres to 1000 °C.