Films of RGO/PMMA composites are under study. Their electrical properties are required to be determined as Rs and Rp values are not same so which one should be used to convert the resistance into resistivity and then into conductivity?
If you use the parallel capacitance/resistance model, you will essentially get the real part of the permittivity form the capacitance and the total conductivity (including the dielectric loss). The complete dielectric behavior cannot be described by such simple model. In order to describe more precisely the actual situation you have to measure the dielectric response (impedance) in a wider frequency (and temperature) range and perform a more complex analysis of the Cole-Cole or Argand diagram. If you are lucky enough you may separate the ohmic conductance from the dielectric loss, but not from a single frequency measurement.
A capacitor is ideally represented by a C in parallel with R.
For an ideal capacitor R is infinity, for a practical capacitor R is finite, and in case it is a leaky capacitor R is very low.
Hence it is always best to take the C in parallel with R in the parallel mode.
------------------------
Now bridges can measure a capacitance in series and parallel modes.
Calculate the impedance of (C in series with Rs), and also (C in parallel with Rp)
you can convert easily from one mode to another. Which means if you know in the series mode, you can express the same in the parallel mode.
this involves a little of mathematics, and simplifications, and you can easily work out.
K. Sreenivas
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Composites