Galvanomagnetic Effects in n-Type Bismuth Telluride

Abstract

The resistivity, Hall coefficients and low field magnetoresistance coefficients associated with current flow in the cleavage planes have been measured at 77°K on a number of n-type specimens of bismuth telluride. The resistivity and Hall coefficient measurements were extended up to room temperature. The experimental results are given and are shown to be reasonably consistent with a many-valley model of the band structure in which the energy minima are situated on the reflection planes. The parameters associated with this model are evaluated and used to relate the two Hall coefficients to the density of carriers. These relations are used to obtain the conductivity mobility of electrons for current flow in the cleavage planes. This mobility varies as T-1 68 over the temperature range 150°K to 300°K and has a value of 1250 cm2sec-1V-1 at room temperature.