Theoretical and experimental analysis methods of the piezostimulated current curves for the determination of the dielectric relaxation time versus pressure and temperature

The dependence of the dielectric relaxation on pressure and temperature can be examined from the variations of the depolarization current of the dielectric, which has been previously subjected to an electric field and high hydrostatic pressure, during the pressure-decrease phase. This is the piezostimulated-current (PSC) method. Different analysis methods of the PSC curves are given in this study. They enable the characteristic parameters of the dielectric to be determined, including the activation volume $\Delta V$, the activation enthalpy $\Delta H$, the activation energy $\Delta E$, and the pre-exponential term ${\tau }_o$ of the Arrhenius-type relaxation time: $\tau ={\tau }_0\exp \left[\frac{(P\Delta V+\Delta E)}{\kappa T}\right]$. An example is given, with results obtained from experiments on 6-po yamide. Good agreement exists between the values determined by different methods of analysis.