How to characterise your material sample and what to note.
The most important types of equipment used to characterise material samples are the following:
Â Â -Â Spectrometers:|R,T| at fixed ω(Fourier –instant. |R(ω),T(ω)|)
Â Â -Â Ellipsometers:polarisation ellipse (VASE –also |R, T|)
Â Â -Â Interferometers:phase(R,T)
Â Â -Â Radio and microwave ranges:Â network analyser
Â Â -Â Radiation sources: laser (multi-F, tunable, pulse), emitter + high-Q-filters,
Â Â -Â Special microscopes (SEM, TEM, AFM, SNOM, etc): internal geometry
Â Â -Â Other: chemical analysis tools
Material parameters like permittivity, permeability etc.Â are derivative parameters and in principle can be obtained from measurable parameters like reflection coefficient, transmission coefficient, resonant frequency and quality factor of a resonator, etc.
The information how to obtain the desired derivative parameters from the measured one can be found in the reports and deliverables of our project "Documents and papers" or starting here .
The recommended procedure for non-EM materials experts is as follows:
1.Â Â Â Check the external geometry and guess the internal geometry of your sample;
2.Â Â Â Choose the equipment owners with the corresponding expertise (or expected expertise) (the menu item "By materials and samples types");
3.Â Â Â Contact the owners and agree the conditions for possible cooperation (the menu item "By laboratories" or the direct link(s) in the table above);
4.Â Â Â Decide what kind of parameters you want to derive;
5.Â Â Â Agree the procedure of measuring (R,T, phase, polarization etc.) for your particular sample in details with the staff involved in your measurements;
6.Â Â Â Get the measured data and do post-processing if needed.
7.Â Â Â Apply the recommended technique to get desired derivative parameters (eps, mu, impedance etc).
8.Â Â Â Redo measurements (e.g. in case of iterative techniques) and make verification experiment if needed.
Some cautions for non-EM experts.
Sometimes the EM characterization labs do not reveal some important information on how they derive material parameters from the measured ones. In most cases this is just protection of their know-how. That is why we promote the approach when you do your derivations yourself starting from the measurement data or ask your partners to follow the publically recommended procedures in characterization parameters derivation like promoted by the ECONAM project.