Frequency and time-domain measurements on humid sand and soil
- Cite this article as:
- Anis, M.K. & Jonscher, A.K. J Mater Sci (1993) 28: 3626. doi:10.1007/BF01159846
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Dielectric measurements are reported in the frequency range 10−3–105 Hz and time range 10−3–103s on samples of sand and soil of different purity, i.e. washed and unwashed, and in a range of relative humidities (RH) between 7% and 97%. All samples show, at low frequencies, a tendency to low-frequency dispersion, with varying degrees of complications from other processes and with a strong influence of purity and RH. At high frequencies there is a low-loss response independent of purity and RH arising from the bulk grains, while at intermediate frequencies evidence is seen for the first time of “dipole-like” response due to the individual grains acting as “giant dipoles”. Time-domain measurements show nearly time-independent charging and discharging currents with “battery-like” response, proving the dominance of electrochemical processes. A discussion is given of the observed behaviour in terms of the current understanding of dielectric processes in humid systems.