Evaluation of the relaxation parameters of interfacial polarization processes in calcite containing dolomite and quartz inclusions by TSDC spectroscopy

The pre-exponential factor of an Arrhenius-type temperature dependence of t he relaxation time of the interfacial polarization processes is sensitive t o the size distribution and the orientation of (conductive) inclusions. An alternative narrow-window thermal sampling thermally stimulated depolarizat ion currents (TSDC) procedure was applied in order to decompose two differe nt overlapping mechanisms of interfacial polarization in a calcite matrix a ccommodating a random distribution of quartz and dolomite inclusions, which are more conductive than the host. The distribution of the activation ener gy and the pre-exponential factors were obtained from the analyses of the T SDC constituents. The orders of magnitude of the relaxation times agree wit h those predicted theoretically. The distributions in the values of the act ivation energy and the pre-exponential factor are discussed with respect to predictions of the theory for conductive ellipsoids dispersed in an insula ting matrix.