THE DIELECTRIC-DISPERSION OF LIQUID-FILLED POROUS SINTERED MATERIALS

We have used a differential effective-medium (DEM) theory to model the dielectric properties of sintered glass beads, impregnated with salty water, in the kHz and MHz ranges. The starting point of the theory is a lattice of touching spheres in pore liquid. The sintering is modell ed by adding solid material and using the DEM method to calculate the dielectric response. Dipolar interactions in the system are treated by using effective depolarization factors, obtained from the dependence of the formation factor on porosity. The frequency dependence of the f ormation factor is in good agreement with experimental data. For the r eal part of the dielectric permittivity, discrepancies arise at low fr equencies. This is probably due to percolation effects.