The temperature dependences of the resistivity, Hall coefficient, and magnetic susceptibility of iron-vanadium-aluminum alloys have been investigated. It has been established that the alloy Fe1.9V1.1Al exhibits semiconductor behavior for the method used to obtain uniform alloys. It is shown that at temperatures below 30K the semiconductor alloy possesses the characteristic low-temperature scale of the dependences observed, which could be responsible for the appearance of a narrow pseudogap in the electron density of states. A simple theoretical description of the effects of a pseudogap is proposed. A consistent fit of the theoretical to the experimental relations made it possible to determine the effective width of the pseudogap (∼1MeV) and its relative depth (∼102).

An anomalous nonmonotonic contribution to the temperature dependence of the electron heat capacity of mercury selenide is detected. This is explained in terms of hybridized electronic states on donor impurities. The observed effect is described by a theory of electron heat capacity based on a quantum Fermi-liquid approach including localization and electron-electron interactions. A quantitative interpretation of the experimental dependences yields values for the parameters of the hybridized states that are consistent with those known from other experiments. A new parameter characterizing the electron-electron interaction in the hybridized states is also found.

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