Investigation of Electrical Characteristics of Thin Silicone–Carbon Coatings

The complex resistance of silicone–carbon films of thickness more than 3 μm is measured on the basis of an analysis of the electrotechnical substitution circuit containing a capacitor and a resistor. It was found that the parameters of the equivalent circuit determined experimentally make it possible to estimate whether the film thickness is greater than 3 μm or not, i.e., to measure the film thickness more than 3 μm. In this case, at frequencies higher that 100 kHz only the capacitive component of the impedance can be measured, whereas the active component associated most likely with the presence of silicon carbide in the film material was detected at lower frequencies. It is shown that for carrying out similar experiments with thinner coatings it is necessary to use a probe covered by a dielectric material with the higher dielectric constant.