Measurement techniques

In some cases, the electric field lines are not uniform at the edge of the sample (dielectric material). The curvature of these lines increases with dielectric thickness for a constant thickness of metal electrodes, while it decreases with decreasing metal electrode thickness for a constant dielectric thickness. When this situation arises, a specific capacitance is measured, which is the sum of the actual material capacitance and the edge effect capacitance (called edge capacitance, C _edge ).

Edge capacitance is additional capacitance caused by non-uniform stray electric field lines at the edge of the sample capacitance. It is therefore necessary to subtract the edge capacitance from the measured...