HgSe:Fe—a mixed-valency system and the problem of the ground state

TLDR: In this paper, the dependence of the electron mobility on the iron impurity content NFe and temperature is studied for three variants of the ordering of Fe3+ ions in crystalline HgSe:Fe, a weakly correlated gas.

Abstract: The dependence of the electron mobility on the iron impurity content NFe and temperature is studied for three variants of the ordering of Fe3+ ions in crystalline HgSe:Fe, a weakly correlated gas, states with near ordering like that in a strongly correlated Coulomb liquid, and long-range ordering. The electron mobilities owing to scattering on the correlated system of Fe3+ ions are determined. The temperature dependence of the mobility is analyzed for electron scattering on fluctuations in the charge density in a system of Fe2+-Fe3+ iron ions with mixed valency, and the correlation length is determined. It is shown that the ordering region for the Fe3+ ions encompasses only the first coordination sphere, i.e., near ordering in the position of the Fe3+ ions is established, as in a liquid. The coupling between the ordering of the Fe3+ ions and the formation of a correlation gap in the density of impurity d-states and its effect on the low-temperature behavior of the electron mobility in HgSe:Fe crystals are examined.