Three-Band Model for the Galvanomagnetic Effects in Bismuth

Abstract

A model of three-band conduction is proposed to explain the magnetic-field dependence of Hall coefficient and the deviation from the H²-dependence of magnetoresistance, which are observed in high purity bismuth at temperatures above the liquid hydrogen temperature. The present model takes into account the effect of thermally-excited light holes as the 3rd carrier. In the model of two-band conduction so far assumed, the field dependence of the galvanomangetic effects in pure bismuth has been interpreted in terms of the unequal number of electrons and holes, while, in the present model, the Hall coefficient is expected to have the magnetic-field dependence even in a perfectly pure bismuth in which the number of electrons and holes is equal.