The polarization phenomenon of EPR without filler at high temperatures

We are studying the dielectric properties of EPR with and without filler. In this paper, we investigate the electrical conductivity and the discharge current of EPR without filler at high temperatures from 60 to 90/spl deg/C. We obtain three parameters /spl alpha/, /spl tau//sub 0/ and /spl epsiv//sub r0/-/spl epsiv//sub r/spl infin//, from the curve fitting of the experimental results for the discharge currents to the theoretical equation. The parameters, /spl alpha/ and /spl epsiv//sub r0/-/spl epsiv//sub r/spl infin//, are almost independent of temperature. In contrast, the characteristic relaxation time, /spl tau//sub 0/, decreases with increasing temperature. The activation energies for the electrical conductivity and relaxation time are 0.74 and 0.89 eV, respectively, being close each to each. Therefore, it is suggested that the dielectric relaxation is associated with the conduction process.