 For a given dielectric, different conduction processes may dominate in different voltage and temperature ranges.For materials such as Si3N4, Al2O3, and SO2, at high temperature and high field regimes, the current "J" is likely due to Poole-Frenkel emission.The detection of Poole-Frenkel emission as the limiting conduction process in a dielectric is usually made studying the slope in the so-called Poole-Frenkel plot, where the logarithm of the current density divided by the field (formula_21) versus the square root of the field (formula_22) is depicted.