Q:I have measured the impedance (EIS) of dielectric material experimentally. I can obtain the Nyquist plot from the built-in function of the spectrometer. I would like to plot the permittivity/ dielectric constant over the range of frequency (dielectric constant Vs frequency curve). I am wondering whether I will be able to calculate the permittivity/ dielectric constant and conductivity from impedance data.
A：
The impedance is obtained by Z* = U*/I*, and the equivalent parallel capacitance by Cp* = 1/jωZ*. The complex permittivity ε* = ε’ - jε’’ = Cp*/C0, where ε’ is the dielectric constant you want, C0
is the vacuum capacitance (or the geometric capacitance, i.e., the
capacitance of the vacuum with the same geometry of your sample). The
complex conductivity σ* = σ’ + jσ’’ = jωε0ε*, where ε0 is the dielectric constant of the vacuum and σ’ is the conductivity you want. To make the results of Z*
of your sample more accurate, the influence of the edge capacitance and
the stray capacitance from the measurement device should be eliminated.
This paper may be more helpful with the question, https://doi.org/10.1063/1.5081842.
https://www.researchgate.net/post/How_can_I_calculate_the_permittivity_dielectric_constant_and_conductivity_from_impedance_data
