Galvanomagnetic Effects in p-Type Bismuth Telluride

Abstract

The resistivity components, Hall coefficients and low field magnetoresistance coefficients have been measured on a number of single crystal specimens of p-type bismuth telluride at 77°k. The results are shown to be consistent with a many-valley form of the valence band for which the energy extrema are on the reflection planes in momentum space. The parameters associated with the model are evaluated and are used to obtain the relations between the Hall coefficients and the density of carriers. The results are used to discuss the variation of the resistivities and the Hall coefficients with temperature over the range 77°k to 290°k and, in particular, to obtain the conductivity mobility for holes for current flow parallel to the cleavage planes. This mobility varies as T-1 98 and, for one specimen, has a value of 515 cm2 volt-1 sec-1 at 290°k.