The field dependence of the complex permittivity of filled composites

The field dependence of the complex permittivity for elastomeric composites filled with a ferroelectric ceramic powder PZT at the power frequency 50 Hz was studied in this work. The critical electric field strength for composites with different filler content was estimated. When the field strength is more than this critical level, the sharp increase in the relaxation time of the polarization process occurs. It was established that the breakdown of composites takes place under the condition of the equality of the real and imaginary parts of the complex permittivity, when the frequency of the external field and the characteristic frequency of the relaxation process are equal to each other.