Magnetic oscillations in semiconductor polycrystals and powders with 2D-conductivity channels

It is shown that magnetic oscillations, i.e. de Haas-van Alphen and Shubnikov-de Haas effects can be observed in semiconductor polycrystals or powders with two-dimensional conductivity channels on grain boundaries or on the surface of crystal particles (in the case of powder). The requirements for the experimental observation of magnetic oscillations are discussed. For typical values of the surface concentration of carriers of 1011-1012 cm-2, oscillations exist in the high magnetic field of 1-10 T. To detect the oscillations of kinetic characteristics (SdH effect) the sample must satisfy two additional requirements, namely, 2D-channels must constitute a conduction cluster penetrating through the whole sample, and the sample thickness must not exceed an average grain size