Galvanomagnetic Effects inp-Type AlSb

Galvanomagnetic measurements have been carried out on single-crystal samples of $p-\mathrm{AlSb}$ in the temperature range from 45 to 500°K using magnetic fields up to 25 kG. The impurity concentration was of the order $(N_A-N_D)\cong 3\times {10}^{16}$ ${\mathrm{cm}}^{-3\mathrm{}}$. An impurity activation energy, extrapolated to 0°K, of 0.033 eV was obtained for the dominant acceptor level from Hall data below 60°K. Weak-field magnetoresistance anisotropy was observed, and the relations $b+c>\mathrm{}0\mathrm{}$ and $d<\mathrm{}0\mathrm{}$ for the inverted Seitz coefficients were found to hold in the entire temperature range. Both the Hall effect and magnetoresistance were found to be strongly field-dependent at the lower temperatures. Using available theoretical values of the warping parameters, the results of the above investigations have been interpreted in terms of a model consisting of two warped valence bands, which are degenerate at the zone center. Analysis of the field dependence of the magnetoresistance yields a light- to heavy-hole carrier concentration ratio of about 8%. A theoretical analysis of the field dependence of the Hall coefficient agrees well with the experimental behavior when this ratio, as well as a heavy-to light-hole lattice mobility ratio of 5, is utilized along with the warping parameters.