1999 Volume 17 Pages 20-37
The paper reviews methods for the electrophysical characterisation of powders and particles and describes in detail many of the laboratory units especially designed for this purpose at the Cagliari University. In particular, the following characteristics can be measured or calculated for powders and particles: (a) electrical conductivity as a function of temperature; (b) thermoelectric potential difference; (c) Seebeck coefficient; (d) electron work function; (e) position of the Fermi level referred to the valence band upper edge; (f) width of the forbidden energy gap; (g) either type of charge carrier concentration (n concentration of electrons in the conduction band, p concentration of free holes in the valence band); (h) either type of charge carrier mobility; (i) electrical charge of powders or single particles; (l) triboelectric charging with different systems. Detailed drawings of the laboratory equipment are provided for each unit used to measure the above-mentioned characteristics, as well as the experimental procedure for both fine powders and single particles. The paper also provides the theory on which the experimental procedure is based and the calculation methods.
