For what systems [a material and a solution] should the EIS scan preferably be scanned from the highest to the lowest, or from the lowest to the highest frequencies? Does that have something to do with the accuracy/reliability of the measurements?, or even with the electrochemical stability of the interfacial system itself?
Endorsing Adel Attia above comment, I would like to add that if you are interested to know about the steady state of your electrochemical system, perform your measurements from high frequency to lower frequency and then repeat the measurement by going from low frequency to high frequency. If you find some sort of hysteresis in both impedance plane plots, you can guess the stability of the electrochemical process.
Now extending the discussion to the possibility of any change at high frequency (as written by Adel Attia), its better to understand this point from perturbation value. From this I mean you should choose low perturbation values like 10mV to avoid such high frequency problem.
for the system what has faraday cage, advanced electrode system and faradaic impedance measurements; lower frequencies can be obtained, however other systems which are not insulated from magnetic waves lower frequencies are scattered. therefore this question depends on your experimental conditions. actually frequency limits can be experimented. for example a solid electrode in a redox probe, from 100000 to 0.05 Hz can be carried out if scattered in lower frequencies occurs than low frequency can be raised(maybe 1 Hz)
Hello, no it should not matter at all if your system is not changing with time. A good test to see if your system is stationary is to perform EIS measurements from high to low frequencies and then back to high frequencies. If the two graphs are the same then your system is considered stationary and your EIS data are meaningful. If you want more details on this please see this paper:
http://pub.iapchem.org/ojs/index.php/JESE/article/view/725
Best regards,
Nicolas
Faysal F. Eliyan Muhammad Nadeem the stability of system is a one fact but how can we know that this specific system can be evaluated using high to low freq or vice versa ? looking forward to your suggestions
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