Circuit equivalent for fitting my data

AI Thread Summary
The discussion focuses on challenges in finding an equivalent circuit for impedance spectroscopy data, particularly at low frequencies where the data values drop while the circuit fit increases. The user has identified that the real part of impedance (Z') needs to reflect a decrease in resistance at low frequencies. Suggestions are sought for circuit elements that exhibit decreasing reactance with lower frequencies. The presence of a dip in Z'' indicates a potential resonant circuit that may need to be considered in the analysis. The goal is to adjust the equivalent circuit to accurately represent the observed data trends.
MarkTheQuark
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TL;DR Summary
Impedancy Spectroscopy
I did a few experiments recently of impedance spectroscopy, and I've gathered some data that i'm having some issues to find an equivalent circuit that can fit the data.

The equivalent circuit that I've got, it's pretty similar with the data (graph and circuit below)

But the problem is, at low frequencies, my data values drop, while the fit from the circuit keeps going up.

Z' represents the real part from the impedance, so basically I need to my equivalent circuit to drop the resistance at low frequencies.

What circuit element, or what I could do, so that I could find an equivalent circuit to my data?
 

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The dip in Z'' suggests there is a resonant circuit somewhere.
 
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