Presently, I am measuring the frequency dependent conductivity and permittivity of a powder subject to water vapor. From my data I would like to estimate the charge carrier density and the mobility. The problem is that I do not know the typical length scales involved. What I can extract are characteristic timescales.
What I know for sure is that all conductivity is surface conductivity: charge carriers running over de surface of powder particles. What I also know is that main carriers are ions desorbing from the solid into mobile surface layer.
Q: Is there a way to extract both the mobility and the charge carrier density independent from the data? If so, how? Do you know a suitable references describing this?
Hi Henk,
Have you solved your problem?
I am trying to solve a similar problem, though with different materials, by applying these methods:
Article Molecular mobility and Li+ conduction in polyester copolymer...
which is similar to this
Article Modeling electrode polarization in dielectric spectroscopy: ...
What do you think?
Cheers
For my problem I did not solve it. In your case you might use the concentration of Li+ ions as the charge carrier density. I guess that you know this amount. You might also need to correct for an H+ contribution in your case.
As you have the number ions, you can estimate from the conduction the 'velocity'/'mobility' of the ions. From your spectra you can obtain characteristic timescale. The combination of 'time scale' and 'velocity' allows you to estimate the involved 'length scale'.
Note:
-> current ~ charge carrier density * charge * velocity
-> current ~ conductivity * field
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