Analysis of Dielectric Spectra

Abstract

The complex dielectric function ɛ*(ω) in its dependence on angular frequency (ω=2πv (v-frequency of the outer electrical field) and temperature originates from different processes: (i) microscopic fluctuations of molecular dipoles [1] (rotational diffusion1), (ii) the propagation of mobile charge carriers (translational diffusion of electrons, holes or ions), and (iii) the separation of charges at interfaces which gives rise to an additional polarization. The latter can take place at inner dielectric boundary layers (Maxwell/Wagner/Sillars-polarization [2, 3] ) on a mesoscopic scale and/or at the external electrodes contacting the sample (electrode polarization) on a macroscopic scale. Its contribution to the dielectric loss can be orders of magnitude larger than the dielectric response due to molecular fluctuations.