EFFECTS OF INTERFACIAL POLARIZATION AND LOADING FACTOR IN DIELECTRIC-LOSS MEASUREMENTS OF COMPOSITES

The effect of the loading factor (the ratio of the conductive volume to the total volume) of a composite can lead to errors of 20% if not considered when interpreting dielectric-loss measurements. Free-carrier interfacial polarization is shown to be unimportant in the interpretation of the Maxwell-Wagner effect for certain classes of composites contrary to currently accepted thought, whereas it can be important in the interpretation of the Dember effect for the same materials. Non-Debye loss in cases where free-carrier interfacial polarization is unimportant is shown to be caused by an additional frequency-dependent component of the conductivity, e.g., that caused by dipole reorientation or conformational rearrangement.