A slim-form, open-ended coaxial probe with an outside diameter of 2.2 mm was used in this study to take local dielectric measurements in soils. The dielectric relaxation strength of bulk water, Δκw, and the DC conductivity of the saturated sample, σmix, are jointly used to characterize the spatial variability of different specimens including glass beads, sand and mica samples, and kaolinite sediments with two different fabric associations. The pore distribution along the sample depth can be inferred from the local Δκw using mixing rules. The directional feature of the interconnected pores is captured in the tortuosity, which is derived from the measured σmix and the DC conductivity of the pore fluid σpf. In kaolinite sediments, the ratio between the sediment and the pore-fluid conductivity not only reveals the spatial variability of the sediment packing but also the relative contribution of the fluid conductivity and the surface conduction to the overall sediment conductivity.
Characterization of dielectric relaxations in CaCu3Ti4O12 via diverse complex planes: Effect of dipole polarization and dc conductivity
