Low-temperature manifestations of hybridized electronic states of iron impurities in the thermoelectric power of mercury selenide

Abstract

The temperature dependence of the Seebeck coefficient (thermoelectric power) of mercury selenide with iron and cobalt impurities is investigated at low temperatures. In crystals with iron impurities at concentrations close to those corresponding to the concentration maximum of the electron mobility, an anomalously strong decrease of the thermoelectric power is observed in a temperature interval below 25K. This decrease is attributed to a manifestation of resonance scattering of electrons in hybridized states at the iron donor impurities. A fitting of the theoretical temperature dependence to the experimental data permits a quantitative interpretation of the experimental results and yields values of the parameters of the hybridized states which agree with those found from investigations of other effects. In crystals with cobalt impurities no anomalies due to manifestations of hybridized electronic states are observed. This finding is in agreement with the conductivity data and implies a lower value of the resonance energy for the cobalt impurities as compared to the iron.