Hopping conduction in FeSi II. deconvolution analyses of temperature-dependent conductivity and its reduced activation energy

Abstract

The deconvolution analysis of the temperature dependence of the reduced activation energy of the conductivity has been utilized for identifying the hopping conduction mechanism in FeSi samples. It is shown that the hopping conduction in the top impurity Hubbard band, i.e., so-called [Formula: see text] conduction, significantly contributes to the conductivity around 50 K. It is also shown that the increase in the effective concentration of the hopping carriers in the bottom Hubbard band causes a step-like increase of the variable range hopping conductivity with increasing temperature for the FeSi sample when the compensation ratio is less than 0.2.