Revisiting the Nature of the Anomalous Temperature Dependence of the Hall Coefficient Observed for Semiconductor Crystals of Bi₂Te₃–Sb₂Te₃ Solid Solutions

Abstract

It is shown based on analysis of the results of experimental investigations that a certain process that provides an increase in the electrical conductivity in the range from 4.2 to 15 K intensifies for some Bi₂Te₃–Sb₂Te₃ crystals, for which the electrical conductivity exceeds 1.5 × 10⁶ S/m. The subsequent decrease in the electrical conductivity with an increase in temperature from 15 K and up to the beginning of domination of the intrinsic conductivity, which is accompanied by an anomalous increase in the Hall coefficient, can be partially caused by a decrease in this process intensity. The assumption is formulated that the influence of plasmon–phonon–polaritons under the conditions of approaching the plasmon energy and band-gap width is able to provide the inverse polarization effect, which is the basis of this process.