Electrical properties of EPR with filler

The authors have investigated the electrical properties, especially the conductivity and the dielectric characteristics in the ultraflow-frequency region of EPR with hard clay. They first investigated the relation between the electrical conductivity and the content of filler. It was found that, as the content of filler was increased, the conductivity decreased initially and then increased abruptly. The authors have explained the decrease and increase in conductivity by the action of carrier traps at the interface between the EPR and filler and the formation of highly conductive paths of the filler between the electrodes, respectively. Secondly, the authors studied the dielectric properties in the ultralow-frequency region which was obtained from the discharge current. The observed variation of the relaxation time with the filler can be interpreted as being due to the variation of cluster shapes in the composite materials