The conductivity versus frequency dependence for the samples
IS4 and IS4В presents two regions: one of frequency-independent
conductivity up to a characteristic frequency u0, and another region
of increasing conductivity with increasing frequency. The
frequency independent conductivity is indicative of non-zero DC
conductivity and non-dielectric behavior. For IS4 and IS4В samples,
the DC conductivities are 8 109 and 5 107 S/cm respectively.
These values are within the range of those observed elsewhere in
composites with the same CB concentrations [