Direct and alternating current conduction mechanisms in unidirectional PZT fibres/epoxy resin composites

The direct current (dc) and alternating current (ac) electrical conductivities of PZT fibres/epoxy resin composites with different PZT fibres content, have been investigated in the temperature range of 80–170 °C and frequency range of 0.1–105 Hz. The charge transport mechanisms and the influence of the fibres rate on electrical conductivity properties have been studied. It was found that: first the conductivity of the composites increases with increasing the fibres content, second dc conductivity of all samples is well described by Arrhenius behavior and third the ac conductivity follows the power law σ ac ( ω , T ) = A ( T ) ω s ( ω , T ) which is typical for charge transport by hopping process. The observed decreasing of the frequency exponent s with increasing temperature suggests that the correlated barrier-hopping model (CBH) is the dominant mechanism.