Full text loading...
-
A Physiochemical Interpretation Of The Cole-Cole Dielectric Model
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 13th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, Feb 2000, cp-200-00060
Abstract
The Cole-Cole dielectric model has been extensively used to fit the observed broadband<br>electrical properties of water-saturated rocks and soils as well as many other types of ionically<br>conducting solids (e.g. colloid suspensions, porous glasses, and biological tissues). The Cole-<br>Cole model was empirically derived and consists of three fitting parameters: the dielectric<br>increment (AZ), a major relaxation time (TO>, and a dispersion parameter (a). In addition to these<br>three parameters it is common to include frequency independent terms for the low-frequency<br>conductivity (oslatic) and the high-frequency permittivity (cm> of the sample. Although the Cole-<br>Cole model has been extensively used for the interpretation of both low-frequency spectral<br>induced-polarization data and high frequency dielectric data, the significance of the model<br>parameters is still not well understood. In this paper we present a physicochemical interpretation<br>of the Cole-Cole dielectric model. It is shown that the Cole-Cole parameters r and a can be<br>related to the mean and variance of the grain size distribution and & is a weighted product of the<br>specific surface area and the surface charge density.